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Lu B, Xia Y, Ren Y, Xie M, Zhou L, Vinai G, Morton SA, Wee ATS, van der Wiel WG, Zhang W, Wong PKJ. When Machine Learning Meets 2D Materials: A Review. Adv Sci (Weinh) 2024; 11:e2305277. [PMID: 38279508 PMCID: PMC10987159 DOI: 10.1002/advs.202305277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 10/21/2023] [Indexed: 01/28/2024]
Abstract
The availability of an ever-expanding portfolio of 2D materials with rich internal degrees of freedom (spin, excitonic, valley, sublattice, and layer pseudospin) together with the unique ability to tailor heterostructures made layer by layer in a precisely chosen stacking sequence and relative crystallographic alignments, offers an unprecedented platform for realizing materials by design. However, the breadth of multi-dimensional parameter space and massive data sets involved is emblematic of complex, resource-intensive experimentation, which not only challenges the current state of the art but also renders exhaustive sampling untenable. To this end, machine learning, a very powerful data-driven approach and subset of artificial intelligence, is a potential game-changer, enabling a cheaper - yet more efficient - alternative to traditional computational strategies. It is also a new paradigm for autonomous experimentation for accelerated discovery and machine-assisted design of functional 2D materials and heterostructures. Here, the study reviews the recent progress and challenges of such endeavors, and highlight various emerging opportunities in this frontier research area.
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Affiliation(s)
- Bin Lu
- ARTIST Lab for Artificial Electronic Materials and Technologies, School of MicroelectronicsNorthwestern Polytechnical UniversityXi'an710072P. R. China
- Yangtze River Delta Research Institute of Northwestern Polytechnical UniversityTaicang215400P. R. China
| | - Yuze Xia
- ARTIST Lab for Artificial Electronic Materials and Technologies, School of MicroelectronicsNorthwestern Polytechnical UniversityXi'an710072P. R. China
- Yangtze River Delta Research Institute of Northwestern Polytechnical UniversityTaicang215400P. R. China
| | - Yuqian Ren
- ARTIST Lab for Artificial Electronic Materials and Technologies, School of MicroelectronicsNorthwestern Polytechnical UniversityXi'an710072P. R. China
- Yangtze River Delta Research Institute of Northwestern Polytechnical UniversityTaicang215400P. R. China
| | - Miaomiao Xie
- ARTIST Lab for Artificial Electronic Materials and Technologies, School of MicroelectronicsNorthwestern Polytechnical UniversityXi'an710072P. R. China
- Yangtze River Delta Research Institute of Northwestern Polytechnical UniversityTaicang215400P. R. China
| | - Liguo Zhou
- ARTIST Lab for Artificial Electronic Materials and Technologies, School of MicroelectronicsNorthwestern Polytechnical UniversityXi'an710072P. R. China
- Yangtze River Delta Research Institute of Northwestern Polytechnical UniversityTaicang215400P. R. China
| | - Giovanni Vinai
- Instituto Officina dei Materiali (IOM)‐CNRLaboratorio TASCTriesteI‐34149Italy
| | - Simon A. Morton
- Advanced Light Source (ALS)Lawrence Berkeley National LaboratoryBerkeleyCA94720USA
| | - Andrew T. S. Wee
- Department of Physics and Centre for Advanced 2D Materials (CA2DM) and Graphene Research Centre (GRC)National University of SingaporeSingapore117542Singapore
| | - Wilfred G. van der Wiel
- NanoElectronics Group, MESA+ Institute for Nanotechnology and BRAINS Center for Brain‐Inspired Nano SystemsUniversity of TwenteEnschede7500AEThe Netherlands
- Institute of PhysicsUniversity of Münster48149MünsterGermany
| | - Wen Zhang
- ARTIST Lab for Artificial Electronic Materials and Technologies, School of MicroelectronicsNorthwestern Polytechnical UniversityXi'an710072P. R. China
- Yangtze River Delta Research Institute of Northwestern Polytechnical UniversityTaicang215400P. R. China
- NanoElectronics Group, MESA+ Institute for Nanotechnology and BRAINS Center for Brain‐Inspired Nano SystemsUniversity of TwenteEnschede7500AEThe Netherlands
| | - Ping Kwan Johnny Wong
- ARTIST Lab for Artificial Electronic Materials and Technologies, School of MicroelectronicsNorthwestern Polytechnical UniversityXi'an710072P. R. China
- Yangtze River Delta Research Institute of Northwestern Polytechnical UniversityTaicang215400P. R. China
- NPU Chongqing Technology Innovation CenterChongqing400000P. R. China
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2
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De Vita A, Sant R, Polewczyk V, van der Laan G, Brookes NB, Kong T, Cava RJ, Rossi G, Vinai G, Panaccione G. Evidence of Temperature-Dependent Interplay between Spin and Orbital Moment in van der Waals Ferromagnet VI 3. Nano Lett 2024; 24:1487-1493. [PMID: 38285518 DOI: 10.1021/acs.nanolett.3c03525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2024]
Abstract
van der Waals materials provide a versatile toolbox for the emergence of new quantum phenomena and fabrication of functional heterostructures. Among them, the trihalide VI3 stands out for its unique magnetic and structural landscape. Here we investigate the spin and orbital magnetic degrees of freedom in the layered ferromagnet VI3 by means of temperature-dependent X-ray absorption spectroscopy and X-ray magnetic circular and linear dichroism. We detect localized electronic states and reduced magnetic dimensionality, due to electronic correlations. We furthermore provide experimental evidence of (a) an unquenched orbital magnetic moment (up to 0.66(7) μB/V atom) in the ferromagnetic state and (b) an instability of the orbital moment in the proximity of the spin reorientation transition. Our results support a coherent picture where electronic correlations give rise to a strong magnetic anisotropy and a large orbital moment and establish VI3 as a prime candidate for the study of orbital quantum effects.
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Affiliation(s)
- Alessandro De Vita
- Dipartimento di Fisica, Universitá degli Studi di Milano, Via Celoria 16, I-20133 Milano, Italy
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, in Area Science Park, S.S.14, km 163.5, I-34149 Trieste, Italy
| | - Roberto Sant
- ESRF, The European Synchrotron, 71 Avenue des Martyrs, CS40220, 38043 Grenoble Cedex 9, France
| | - Vincent Polewczyk
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, in Area Science Park, S.S.14, km 163.5, I-34149 Trieste, Italy
| | - Gerrit van der Laan
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, U.K
| | - Nicholas B Brookes
- ESRF, The European Synchrotron, 71 Avenue des Martyrs, CS40220, 38043 Grenoble Cedex 9, France
| | - Tai Kong
- Department of Chemistry, Princeton University, Princeton, New Jersey 08540, United States
| | - Robert J Cava
- Department of Chemistry, Princeton University, Princeton, New Jersey 08540, United States
| | - Giorgio Rossi
- Dipartimento di Fisica, Universitá degli Studi di Milano, Via Celoria 16, I-20133 Milano, Italy
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, in Area Science Park, S.S.14, km 163.5, I-34149 Trieste, Italy
| | - Giovanni Vinai
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, in Area Science Park, S.S.14, km 163.5, I-34149 Trieste, Italy
| | - Giancarlo Panaccione
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, in Area Science Park, S.S.14, km 163.5, I-34149 Trieste, Italy
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3
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Mazzola F, Enzner S, Eck P, Bigi C, Jugovac M, Cojocariu I, Feyer V, Shu Z, Pierantozzi GM, De Vita A, Carrara P, Fujii J, King PDC, Vinai G, Orgiani P, Cacho C, Watson MD, Rossi G, Vobornik I, Kong T, Di Sante D, Sangiovanni G, Panaccione G. Observation of Termination-Dependent Topological Connectivity in a Magnetic Weyl Kagome Lattice. Nano Lett 2023; 23:8035-8042. [PMID: 37638737 PMCID: PMC10510577 DOI: 10.1021/acs.nanolett.3c02022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 08/21/2023] [Indexed: 08/29/2023]
Abstract
Engineering surfaces and interfaces of materials promises great potential in the field of heterostructures and quantum matter designers, with the opportunity to drive new many-body phases that are absent in the bulk compounds. Here, we focus on the magnetic Weyl kagome system Co3Sn2S2 and show how for the terminations of different samples the Weyl points connect differently, still preserving the bulk-boundary correspondence. Scanning tunneling microscopy has suggested such a scenario indirectly, and here, we probe the Fermiology of Co3Sn2S2 directly, by linking it to its real space surface distribution. By combining micro-ARPES and first-principles calculations, we measure the energy-momentum spectra and the Fermi surfaces of Co3Sn2S2 for different surface terminations and show the existence of topological features depending on the top-layer electronic environment. Our work helps to define a route for controlling bulk-derived topological properties by means of surface electrostatic potentials, offering a methodology for using Weyl kagome metals in responsive magnetic spintronics.
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Affiliation(s)
- Federico Mazzola
- Department
of Molecular Sciences and Nanosystems, Ca’
Foscari University of Venice, 30172 Venice, Italy
| | - Stefan Enzner
- Institut
für Theoretische Physik und Astrophysik and Würzburg-Dresden
Cluster of Excellence ct.qmat, Universität
Würzburg, 97074 Würzburg, Germany
| | - Philipp Eck
- Institut
für Theoretische Physik und Astrophysik and Würzburg-Dresden
Cluster of Excellence ct.qmat, Universität
Würzburg, 97074 Würzburg, Germany
| | - Chiara Bigi
- School
of Physics and Astronomy, University of
St Andrews, St Andrews KY16 9SS, United
Kingdom
| | - Matteo Jugovac
- Elettra
Sincrotrone Trieste S.C.p.A. S. S. 14, km 163.5, 34149 Trieste, Italy
| | - Iulia Cojocariu
- Elettra
Sincrotrone Trieste S.C.p.A. S. S. 14, km 163.5, 34149 Trieste, Italy
- Università degli studi di Trieste Via A. Valerio 2, 34127 Trieste, Italy
| | - Vitaliy Feyer
- Forschungszentrum Juelich GmBH PGI-6Leo Brandt Strasse, 52425 Juelich, Germany
| | - Zhixue Shu
- Department
of Physics, University of Arizona, Tucson, Arizona 85721, United States
| | - Gian Marco Pierantozzi
- Istituto
Officina dei Materiali, Consiglio Nazionale
delle Ricerche, Trieste I-34149, Italy
| | - Alessandro De Vita
- Dipartimento
di Fisica Universitá di Milano, Via Celoria 16, Milano 20133, Italy
| | - Pietro Carrara
- Dipartimento
di Fisica Universitá di Milano, Via Celoria 16, Milano 20133, Italy
| | - Jun Fujii
- Istituto
Officina dei Materiali, Consiglio Nazionale
delle Ricerche, Trieste I-34149, Italy
| | - Phil D. C. King
- School
of Physics and Astronomy, University of
St Andrews, St Andrews KY16 9SS, United
Kingdom
| | - Giovanni Vinai
- Istituto
Officina dei Materiali, Consiglio Nazionale
delle Ricerche, Trieste I-34149, Italy
| | - Pasquale Orgiani
- Istituto
Officina dei Materiali, Consiglio Nazionale
delle Ricerche, Trieste I-34149, Italy
| | - Cephise Cacho
- Diamond
Light
Source, Harwell Campus, Didcot OX11 0DE, United Kingdom
| | - Matthew D. Watson
- Diamond
Light
Source, Harwell Campus, Didcot OX11 0DE, United Kingdom
| | - Giorgio Rossi
- Dipartimento
di Fisica Universitá di Milano, Via Celoria 16, Milano 20133, Italy
| | - Ivana Vobornik
- Istituto
Officina dei Materiali, Consiglio Nazionale
delle Ricerche, Trieste I-34149, Italy
| | - Tai Kong
- Department
of Physics, University of Arizona, Tucson, Arizona 85721, United States
| | - Domenico Di Sante
- Department
of Physics and Astronomy, University of
Bologna, 40127 Bologna, Italy
- Center
for Computational Quantum Physics, Flatiron
Institute, 162 5th Avenue, New York, New York 10010, United States
| | - Giorgio Sangiovanni
- Institut
für Theoretische Physik und Astrophysik and Würzburg-Dresden
Cluster of Excellence ct.qmat, Universität
Würzburg, 97074 Würzburg, Germany
| | - Giancarlo Panaccione
- Istituto
Officina dei Materiali, Consiglio Nazionale
delle Ricerche, Trieste I-34149, Italy
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4
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Sant R, De Vita A, Polewczyk V, Pierantozzi GM, Mazzola F, Vinai G, van der Laan G, Panaccione G, Brookes NB. Anisotropic hybridization probed by polarization dependent x-ray absorption spectroscopy in VI 3van der Waals Mott ferromagnet. J Phys Condens Matter 2023. [PMID: 37364587 DOI: 10.1088/1361-648x/ace1bf] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/28/2023]
Abstract
Polarization dependent x-ray absorption spectroscopy was used to study the magnetic ground state and the orbital occupation in bulk-phase VI3 van der Waals crystals below and above the ferromagnetic and structural transitions. X-ray natural linear dichroism and X-ray magnetic circular dichroism spectra acquired at the V L2,3 edges are compared against multiplet cluster calculations within the frame of the ligand field theory to quantify the intra-atomic electronic interactions at play and evaluate the effects of symmetry reduction occurring in a trigonally distorted VI6 unit. We observed a non zero linear dichroism proving the presence of an anisotropic charge density distribution around the V3+ ion due to the unbalanced hybridization between the Vanadium and the ligand states. Such hybridization acts as an effective trigonal crystal field, slightly lifting the degeneracy of the t22g ground state. However, the energy splitting associated to the distortion underestimates the experimental band gap, suggesting that the insulating ground state is stabilized by Mott correlation effects rather than via a Jahn-Teller mechanism. Our results clarify the role of the distortion in VI3 and establish a benchmark for the study of the spectroscopic properties of other van der Waals halides, including emerging 2D materials with mono and few-layers thickness, whose fundamental properties might be altered by reduced dimensions and interface proximity.
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Affiliation(s)
- Roberto Sant
- Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy, Milano, 20133, ITALY
| | - Alessandro De Vita
- Istituto Officina dei Materiali Consiglio Nazionale delle Ricerche, Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, in Area Science Park, S.S.14, Km 163.5, I-34149 Trieste, Italy, Trieste, Trieste, 34149, ITALY
| | - Vincent Polewczyk
- Istituto Officina dei Materiali Consiglio Nazionale delle Ricerche, Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, in Area Science Park, S.S.14, Km 163.5, I-34149 Trieste, Italy, Trieste, Trieste, 34149, ITALY
| | - Gian Marco Pierantozzi
- Istituto Officina dei Materiali Consiglio Nazionale delle Ricerche, Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, in Area Science Park, S.S.14, Km 163.5, I-34149 Trieste, Italy, Trieste, Trieste, 34149, ITALY
| | - Federico Mazzola
- Istituto Officina dei Materiali Consiglio Nazionale delle Ricerche, Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, in Area Science Park, S.S.14, Km 163.5, I-34149 Trieste, Italy, Trieste, Trieste, 34149, ITALY
| | - Giovanni Vinai
- Istituto Officina dei Materiali Consiglio Nazionale delle Ricerche, CNR-Istituto Officina dei Materiali, Laboratorio TASC in Area Science Park, S.S. 14 Km 163.5 in AREA Science Park, Trieste, Trieste, 34149, ITALY
| | - Gerrit van der Laan
- Science Division, Diamond Light Source Ltd, Harwell Science & Innovation Campus, Didcot, Oxfordshire, OX11 0DE, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND
| | - Giancarlo Panaccione
- Istituto Officina dei Materiali Consiglio Nazionale delle Ricerche, Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, in Area Science Park, S.S.14, Km 163.5, I-34149 Trieste, Italy, Trieste, Trieste, 34149, ITALY
| | - N B Brookes
- European Synchrotron Radiation Facility, ESRF, The European Synchrotron, 71 Avenue des Martyrs, CS40220, 38043 Grenoble Cedex 9, France, Grenoble, 38043, FRANCE
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5
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Rath M, Mezhoud M, El Khaloufi O, Lebedev O, Cardin J, Labbé C, Gourbilleau F, Polewczyk V, Vinai G, Torelli P, Fouchet A, David A, Prellier W, Lüders U. Artificial Aging of Thin Films of the Indium-Free Transparent Conducting Oxide SrVO 3. ACS Appl Mater Interfaces 2023; 15:20240-20251. [PMID: 37067020 DOI: 10.1021/acsami.3c02421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
SrVO3 (SVO) is a prospective candidate to replace the conventional indium tin oxide (ITO) among the new generation of transparent conducting oxide (TCO) materials. In this study, the structural, electrical, and optical properties of SVO thin films, both epitaxial and polycrystalline, are determined during and after heat treatments in the 150-250 °C range and under ambient environment in order to explore the chemical stability of this material. The use of these relatively low temperatures speeds up the natural aging of the films and allows following the evolution of their related properties. The combination of techniques rather sensitive to the film surface and of techniques sampling the film volume will emphasize the presence of a surface oxidation evolving in time at low annealing temperatures, whereas the perovskite phase is destroyed throughout the film for treatments above 200 °C. The present study is designed to understand the thermal degradation and long-term stability issues of vanadate-based TCOs and to identify technologically viable solutions for the application of this group as new TCOs.
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Affiliation(s)
- Martando Rath
- Normandie Univ, ENSICAEN, UNICAEN, CNRS, CRISMAT, 6, boulevard du Maréchal Juin, F-14050 Caen, France
| | - Moussa Mezhoud
- Normandie Univ, ENSICAEN, UNICAEN, CNRS, CRISMAT, 6, boulevard du Maréchal Juin, F-14050 Caen, France
| | - Oualyd El Khaloufi
- Normandie Univ, ENSICAEN, UNICAEN, CNRS, CRISMAT, 6, boulevard du Maréchal Juin, F-14050 Caen, France
| | - Oleg Lebedev
- Normandie Univ, ENSICAEN, UNICAEN, CNRS, CRISMAT, 6, boulevard du Maréchal Juin, F-14050 Caen, France
| | - Julien Cardin
- CIMAP, CNRS, ENSICAEN, UNICAEN, Normandie Univ, 6, boulevard du Maréchal Juin, F-14050 Caen, France
| | - Christophe Labbé
- CIMAP, CNRS, ENSICAEN, UNICAEN, Normandie Univ, 6, boulevard du Maréchal Juin, F-14050 Caen, France
| | - Fabrice Gourbilleau
- CIMAP, CNRS, ENSICAEN, UNICAEN, Normandie Univ, 6, boulevard du Maréchal Juin, F-14050 Caen, France
| | - Vincent Polewczyk
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, Area Science Park, S.S.14, km 163.5, I-34149 Trieste, Italy
| | - Giovanni Vinai
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, Area Science Park, S.S.14, km 163.5, I-34149 Trieste, Italy
| | - Piero Torelli
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, Area Science Park, S.S.14, km 163.5, I-34149 Trieste, Italy
| | - Arnaud Fouchet
- Normandie Univ, ENSICAEN, UNICAEN, CNRS, CRISMAT, 6, boulevard du Maréchal Juin, F-14050 Caen, France
| | - Adrian David
- Normandie Univ, ENSICAEN, UNICAEN, CNRS, CRISMAT, 6, boulevard du Maréchal Juin, F-14050 Caen, France
| | - Wilfrid Prellier
- Normandie Univ, ENSICAEN, UNICAEN, CNRS, CRISMAT, 6, boulevard du Maréchal Juin, F-14050 Caen, France
| | - Ulrike Lüders
- Normandie Univ, ENSICAEN, UNICAEN, CNRS, CRISMAT, 6, boulevard du Maréchal Juin, F-14050 Caen, France
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6
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Brioschi M, Carrara P, Polewczyk V, Dagur D, Vinai G, Parisse P, Dal Zilio S, Panaccione G, Rossi G, Cucini R. Multidetection scheme for transient-grating-based spectroscopy. Opt Lett 2023; 48:167-170. [PMID: 36563397 DOI: 10.1364/ol.476958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 11/08/2022] [Indexed: 06/17/2023]
Abstract
Time-resolved optical spectroscopy represents an effective non-invasive approach to investigate the interplay of different degrees of freedom, which plays a key role in the development of novel functional materials. Here, we present magneto-acoustic data on Ni thin films on SiO2 as obtained by a versatile pump-probe setup that combines transient grating spectroscopy with time-resolved magnetic polarimetry. The possibility to easily switch from a pulsed to continuous wave probe allows probing of acoustic and magnetization dynamics on a broad time scale, in both transmission and reflection geometry.
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7
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De Vita A, Nguyen TTP, Sant R, Pierantozzi GM, Amoroso D, Bigi C, Polewczyk V, Vinai G, Nguyen LT, Kong T, Fujii J, Vobornik I, Brookes NB, Rossi G, Cava RJ, Mazzola F, Yamauchi K, Picozzi S, Panaccione G. Influence of Orbital Character on the Ground State Electronic Properties in the van Der Waals Transition Metal Iodides VI 3 and CrI 3. Nano Lett 2022; 22:7034-7041. [PMID: 36039834 PMCID: PMC9479147 DOI: 10.1021/acs.nanolett.2c01922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Two-dimensional van der Waals magnetic semiconductors display emergent chemical and physical properties and hold promise for novel optical, electronic and magnetic "few-layers" functionalities. Transition-metal iodides such as CrI3 and VI3 are relevant for future electronic and spintronic applications; however, detailed experimental information on their ground state electronic properties is lacking often due to their challenging chemical environment. By combining X-ray electron spectroscopies and first-principles calculations, we report a complete determination of CrI3 and VI3 electronic ground states. We show that the transition metal-induced orbital filling drives the stabilization of distinct electronic phases: a wide bandgap in CrI3 and a Mott insulating state in VI3. Comparison of surface-sensitive (angular-resolved photoemission spectroscopy) and bulk-sensitive (X-ray absorption spectroscopy) measurements in VI3 reveals a surface-only V2+ oxidation state, suggesting that ground state electronic properties are strongly influenced by dimensionality effects. Our results have direct implications in band engineering and layer-dependent properties of two-dimensional systems.
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Affiliation(s)
- Alessandro De Vita
- Laboratorio TASC, in Area Science Park, Istituto Officina dei Materiali (IOM)-CNR, S.S.14, Km 163.5, I-34149 Trieste, Italy
- Dipartimento di Fisica, Università di Milano, Via Celoria 16, I-20133 Milano, Italy
| | - Thao Thi Phuong Nguyen
- Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka Ibaraki, Osaka 567-0047, Japan
- Department of Precision Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Roberto Sant
- ESRF, The European Synchrotron, 71 Avenue des Martyrs, F-38043 Grenoble, France
| | - Gian Marco Pierantozzi
- Laboratorio TASC, in Area Science Park, Istituto Officina dei Materiali (IOM)-CNR, S.S.14, Km 163.5, I-34149 Trieste, Italy
| | - Danila Amoroso
- Consiglio Nazionale delle Ricerche (CNR-SPIN), Unità di Ricerca presso Terzi c/o Università "G. D'Annunzio", 66100 Chieti, Italy
- NanoMat/Q-mat/CESAM, Université de Liège, B-4000 Liege, Belgium
| | - Chiara Bigi
- Laboratorio TASC, in Area Science Park, Istituto Officina dei Materiali (IOM)-CNR, S.S.14, Km 163.5, I-34149 Trieste, Italy
- School of Physics and Astronomy, University of St. Andrews, St. Andrews KY16 9SS, United Kingdom
| | - Vincent Polewczyk
- Laboratorio TASC, in Area Science Park, Istituto Officina dei Materiali (IOM)-CNR, S.S.14, Km 163.5, I-34149 Trieste, Italy
| | - Giovanni Vinai
- Laboratorio TASC, in Area Science Park, Istituto Officina dei Materiali (IOM)-CNR, S.S.14, Km 163.5, I-34149 Trieste, Italy
| | - Loi T Nguyen
- Department of Chemistry, Princeton University, Princeton, New Jersey 08540, United States
| | - Tai Kong
- Department of Chemistry, Princeton University, Princeton, New Jersey 08540, United States
| | - Jun Fujii
- Laboratorio TASC, in Area Science Park, Istituto Officina dei Materiali (IOM)-CNR, S.S.14, Km 163.5, I-34149 Trieste, Italy
| | - Ivana Vobornik
- Laboratorio TASC, in Area Science Park, Istituto Officina dei Materiali (IOM)-CNR, S.S.14, Km 163.5, I-34149 Trieste, Italy
| | - Nicholas B Brookes
- ESRF, The European Synchrotron, 71 Avenue des Martyrs, F-38043 Grenoble, France
| | - Giorgio Rossi
- Laboratorio TASC, in Area Science Park, Istituto Officina dei Materiali (IOM)-CNR, S.S.14, Km 163.5, I-34149 Trieste, Italy
- Dipartimento di Fisica, Università di Milano, Via Celoria 16, I-20133 Milano, Italy
| | - Robert J Cava
- Department of Chemistry, Princeton University, Princeton, New Jersey 08540, United States
| | - Federico Mazzola
- Laboratorio TASC, in Area Science Park, Istituto Officina dei Materiali (IOM)-CNR, S.S.14, Km 163.5, I-34149 Trieste, Italy
| | - Kunihiko Yamauchi
- Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka Ibaraki, Osaka 567-0047, Japan
- Department of Precision Engineering, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Silvia Picozzi
- Consiglio Nazionale delle Ricerche (CNR-SPIN), Unità di Ricerca presso Terzi c/o Università "G. D'Annunzio", 66100 Chieti, Italy
| | - Giancarlo Panaccione
- Laboratorio TASC, in Area Science Park, Istituto Officina dei Materiali (IOM)-CNR, S.S.14, Km 163.5, I-34149 Trieste, Italy
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8
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Chaluvadi SK, Polewczyk V, Petrov AY, Vinai G, Braglia L, Diez JM, Pierron V, Perna P, Mechin L, Torelli P, Orgiani P. Electronic Properties of Fully Strained La 1-x Sr x MnO 3 Thin Films Grown by Molecular Beam Epitaxy (0.15 ≤ x ≤ 0.45). ACS Omega 2022; 7:14571-14578. [PMID: 35557663 PMCID: PMC9088787 DOI: 10.1021/acsomega.1c06529] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 02/04/2022] [Indexed: 06/15/2023]
Abstract
The structural, electronic, and magnetic properties of Sr-hole-doped epitaxial La1-x Sr x MnO3 (0.15 ≤ x ≤ 0.45) thin films deposited using the molecular beam epitaxy technique on 4° vicinal STO (001) substrates are probed by the combination of X-ray diffraction and various synchrotron-based spectroscopy techniques. The structural characterizations evidence a significant shift in the LSMO (002) peak to the higher diffraction angles owing to the increase in Sr doping concentrations in thin films. The nature of the LSMO Mn mixed-valence state was estimated from X-ray photoemission spectroscopy together with the relative changes in the Mn L2,3 edges observed in X-ray absorption spectroscopy (XAS), both strongly affected by doping. CTM4XAS simulations at the XAS Mn L2,3 edges reveal the combination of epitaxial strain, and different MnO6 crystal field splitting give rise to a peak at ∼641 eV. The observed changes in the occupancy of the eg and the t2g orbitals as well as their binding energy positions toward the Fermi level with hole doping are discussed. The room-temperature magnetic properties were probed at the end by circular dichroism.
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Affiliation(s)
- Sandeep Kumar Chaluvadi
- Istituto
Officina dei Materiali (IOM)−CNR, Laboratorio TASC, Area Science Park, S.S.14, km 163.5, I-34149 Trieste, Italy
| | - Vincent Polewczyk
- Istituto
Officina dei Materiali (IOM)−CNR, Laboratorio TASC, Area Science Park, S.S.14, km 163.5, I-34149 Trieste, Italy
| | - Aleksandr Yu Petrov
- Istituto
Officina dei Materiali (IOM)−CNR, Laboratorio TASC, Area Science Park, S.S.14, km 163.5, I-34149 Trieste, Italy
| | - Giovanni Vinai
- Istituto
Officina dei Materiali (IOM)−CNR, Laboratorio TASC, Area Science Park, S.S.14, km 163.5, I-34149 Trieste, Italy
| | - Luca Braglia
- Istituto
Officina dei Materiali (IOM)−CNR, Laboratorio TASC, Area Science Park, S.S.14, km 163.5, I-34149 Trieste, Italy
| | | | - Victor Pierron
- Normandie
Univ, UNICAEN, ENSICAEN, CNRS, GREYC (UMR 6072), 14000 Caen, France
| | - Paolo Perna
- IMDEA-Nanociencia, Campus de Cantoblanco, 28049 Madrid, Spain
| | - Laurence Mechin
- Normandie
Univ, UNICAEN, ENSICAEN, CNRS, GREYC (UMR 6072), 14000 Caen, France
| | - Piero Torelli
- Istituto
Officina dei Materiali (IOM)−CNR, Laboratorio TASC, Area Science Park, S.S.14, km 163.5, I-34149 Trieste, Italy
| | - Pasquale Orgiani
- Istituto
Officina dei Materiali (IOM)−CNR, Laboratorio TASC, Area Science Park, S.S.14, km 163.5, I-34149 Trieste, Italy
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9
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Dmitriyeva A, Mikheev V, Zarubin S, Chouprik A, Vinai G, Polewczyk V, Torelli P, Matveyev Y, Schlueter C, Karateev I, Yang Q, Chen Z, Tao L, Tsymbal EY, Zenkevich A. Magnetoelectric Coupling at the Ni/Hf 0.5Zr 0.5O 2 Interface. ACS Nano 2021; 15:14891-14902. [PMID: 34468129 DOI: 10.1021/acsnano.1c05001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Composite multiferroics containing ferroelectric and ferromagnetic components often have much larger magnetoelectric coupling compared to their single-phase counterparts. Doped or alloyed HfO2-based ferroelectrics may serve as a promising component in composite multiferroic structures potentially feasible for technological applications. Recently, a strong charge-mediated magnetoelectric coupling at the Ni/HfO2 interface has been predicted using density functional theory calculations. Here, we report on the experimental evidence of such magnetoelectric coupling at the Ni/Hf0.5Zr0.5O2(HZO) interface. Using a combination of operando XAS/XMCD and HAXPES/MCDAD techniques, we probe element-selectively the local magnetic properties at the Ni/HZO interface in functional Au/Co/Ni/HZO/W capacitors and demonstrate clear evidence of the ferroelectric polarization effect on the magnetic response of a nanometer-thick Ni marker layer. The observed magnetoelectric effect and the electronic band lineup of the Ni/HZO interface are interpreted based on the results of our theoretical modeling. It elucidates the critical role of an ultrathin NiO interlayer, which controls the sign of the magnetoelectric effect as well as provides a realistic band offset at the Ni/HZO interface, in agreement with the experiment. Our results hold promise for the use of ferroelectric HfO2-based composite multiferroics for the design of multifunctional devices compatible with modern semiconductor technology.
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Affiliation(s)
- Anna Dmitriyeva
- Moscow Institute of Physics and Technology, 9, Institutskiy lane, Dolgoprudny, Moscow Region, 141700, Russia
| | - Vitalii Mikheev
- Moscow Institute of Physics and Technology, 9, Institutskiy lane, Dolgoprudny, Moscow Region, 141700, Russia
| | - Sergei Zarubin
- Moscow Institute of Physics and Technology, 9, Institutskiy lane, Dolgoprudny, Moscow Region, 141700, Russia
| | - Anastasia Chouprik
- Moscow Institute of Physics and Technology, 9, Institutskiy lane, Dolgoprudny, Moscow Region, 141700, Russia
| | - Giovanni Vinai
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, Area Science Park, S.S. 14 km 163.5, Trieste I-34149, Italy
| | - Vincent Polewczyk
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, Area Science Park, S.S. 14 km 163.5, Trieste I-34149, Italy
| | - Piero Torelli
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, Area Science Park, S.S. 14 km 163.5, Trieste I-34149, Italy
| | - Yury Matveyev
- Deutsches Elektronen-Synchrotron, 85 Notkestraße, Hamburg, D-22607, Germany
| | | | - Igor Karateev
- National Research Center "Kurchatov Institute", Moscow, 123182, Russia
| | - Qiong Yang
- School of Materials Science and Engineering, Xiangtan University, Xiangtan, Hunan 411105, China
| | - Zhaojin Chen
- School of Materials Science and Engineering, Xiangtan University, Xiangtan, Hunan 411105, China
| | - Lingling Tao
- Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States
| | - Evgeny Y Tsymbal
- Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States
| | - Andrei Zenkevich
- Moscow Institute of Physics and Technology, 9, Institutskiy lane, Dolgoprudny, Moscow Region, 141700, Russia
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10
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Polewczyk V, Magrin Maffei R, Vinai G, Lo Cicero M, Prato S, Capaldo P, Dal Zilio S, di Bona A, Paolicelli G, Mescola A, D’Addato S, Torelli P, Benedetti S. ZnO Thin Films Growth Optimization for Piezoelectric Application. Sensors (Basel) 2021; 21:6114. [PMID: 34577322 PMCID: PMC8472809 DOI: 10.3390/s21186114] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 09/02/2021] [Accepted: 09/08/2021] [Indexed: 01/10/2023]
Abstract
The piezoelectric response of ZnO thin films in heterostructure-based devices is strictly related to their structure and morphology. We optimize the fabrication of piezoelectric ZnO to reduce its surface roughness, improving the crystalline quality, taking into consideration the role of the metal electrode underneath. The role of thermal treatments, as well as sputtering gas composition, is investigated by means of atomic force microscopy and x-ray diffraction. The results show an optimal reduction in surface roughness and at the same time a good crystalline quality when 75% O2 is introduced in the sputtering gas and deposition is performed between room temperature and 573 K. Subsequent annealing at 773 K further improves the film quality. The introduction of Ti or Pt as bottom electrode maintains a good surface and crystalline quality. By means of piezoelectric force microscope, we prove a piezoelectric response of the film in accordance with the literature, in spite of the low ZnO thickness and the reduced grain size, with a unipolar orientation and homogenous displacement when deposited on Ti electrode.
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Affiliation(s)
- Vincent Polewczyk
- Laboratorio TASC, Istituto Officina dei Materiali (IOM)-CNR, 34149 Trieste, Italy; (G.V.); (P.C.); (S.D.Z.); (P.T.)
| | - Riccardo Magrin Maffei
- Istituto Nanoscienze-CNR, Via Campi 213/a, 41125 Modena, Italy; (R.M.M.); (A.d.B.); (G.P.); (A.M.); (S.D.)
- Dipartimento di Scienze Fisiche Informatiche Matematiche, Università di Modena e Reggio Emilia, Via Campi 213/a, 41125 Modena, Italy
| | - Giovanni Vinai
- Laboratorio TASC, Istituto Officina dei Materiali (IOM)-CNR, 34149 Trieste, Italy; (G.V.); (P.C.); (S.D.Z.); (P.T.)
| | - Matteo Lo Cicero
- A.P.E. Research srl, Area Science Park, Basovizza, ss14 Km 163.5, 34149 Trieste, Italy; (M.L.C.); (S.P.)
| | - Stefano Prato
- A.P.E. Research srl, Area Science Park, Basovizza, ss14 Km 163.5, 34149 Trieste, Italy; (M.L.C.); (S.P.)
| | - Pietro Capaldo
- Laboratorio TASC, Istituto Officina dei Materiali (IOM)-CNR, 34149 Trieste, Italy; (G.V.); (P.C.); (S.D.Z.); (P.T.)
- Dipartimento di Fisica e Astronomia, Università di Padova, Via F Marzolo 8, 35131 Padova, Italy
| | - Simone Dal Zilio
- Laboratorio TASC, Istituto Officina dei Materiali (IOM)-CNR, 34149 Trieste, Italy; (G.V.); (P.C.); (S.D.Z.); (P.T.)
| | - Alessandro di Bona
- Istituto Nanoscienze-CNR, Via Campi 213/a, 41125 Modena, Italy; (R.M.M.); (A.d.B.); (G.P.); (A.M.); (S.D.)
| | - Guido Paolicelli
- Istituto Nanoscienze-CNR, Via Campi 213/a, 41125 Modena, Italy; (R.M.M.); (A.d.B.); (G.P.); (A.M.); (S.D.)
| | - Andrea Mescola
- Istituto Nanoscienze-CNR, Via Campi 213/a, 41125 Modena, Italy; (R.M.M.); (A.d.B.); (G.P.); (A.M.); (S.D.)
| | - Sergio D’Addato
- Istituto Nanoscienze-CNR, Via Campi 213/a, 41125 Modena, Italy; (R.M.M.); (A.d.B.); (G.P.); (A.M.); (S.D.)
- Dipartimento di Scienze Fisiche Informatiche Matematiche, Università di Modena e Reggio Emilia, Via Campi 213/a, 41125 Modena, Italy
| | - Piero Torelli
- Laboratorio TASC, Istituto Officina dei Materiali (IOM)-CNR, 34149 Trieste, Italy; (G.V.); (P.C.); (S.D.Z.); (P.T.)
| | - Stefania Benedetti
- Istituto Nanoscienze-CNR, Via Campi 213/a, 41125 Modena, Italy; (R.M.M.); (A.d.B.); (G.P.); (A.M.); (S.D.)
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11
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Giaconi N, Sorrentino AL, Poggini L, Lupi M, Polewczyk V, Vinai G, Torelli P, Magnani A, Sessoli R, Menichetti S, Sorace L, Viglianisi C, Mannini M. Stabilization of an Enantiopure Sub-monolayer of Helicene Radical Cations on a Au(111) Surface through Noncovalent Interactions. Angew Chem Int Ed Engl 2021; 60:15276-15280. [PMID: 33904633 PMCID: PMC8362206 DOI: 10.1002/anie.202103710] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 04/15/2021] [Indexed: 12/16/2022]
Abstract
In the past few years, the chirality and magnetism of molecules have received notable interest for the development of novel molecular devices. Chiral helicenes combine both these properties, and thus their nanostructuration is the first step toward developing new multifunctional devices. Here, we present a novel strategy to deposit a sub‐monolayer of enantiopure thia[4]helicene radical cations on a pre‐functionalized Au(111) substrate. This approach results in both the paramagnetic character and the chemical structure of these molecules being maintained at the nanoscale, as demonstrated by in‐house characterizations. Furthermore, synchrotron‐based X‐ray natural circular dichroism confirmed that the handedness of the thia[4]helicene is preserved on the surface.
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Affiliation(s)
- Niccolò Giaconi
- Department of Chemistry "Ugo Schiff" and INSTM Research Unit, University of Florence, Via della Lastruccia 3-13, 50019, Sesto Fiorentino, Italy.,Department of Industrial Engineering and INSTM Research Unit, University of Florence, Via Santa Marta 3, 50139, Florence, Italy
| | - Andrea Luigi Sorrentino
- Department of Chemistry "Ugo Schiff" and INSTM Research Unit, University of Florence, Via della Lastruccia 3-13, 50019, Sesto Fiorentino, Italy.,Department of Industrial Engineering and INSTM Research Unit, University of Florence, Via Santa Marta 3, 50139, Florence, Italy
| | - Lorenzo Poggini
- Department of Chemistry "Ugo Schiff" and INSTM Research Unit, University of Florence, Via della Lastruccia 3-13, 50019, Sesto Fiorentino, Italy.,Istituto di Chimica dei Composti Organometallici (ICCOM), CNR, Via Madonna del Piano, 10, 50019, Sesto Fiorentino, Italy
| | - Michela Lupi
- Department of Chemistry "Ugo Schiff" and INSTM Research Unit, University of Florence, Via della Lastruccia 3-13, 50019, Sesto Fiorentino, Italy
| | - Vincent Polewczyk
- Istituto Officina dei Materiali (IOM), CNR, Laboratorio TASC, Area Science Park, S.S. 14 km 163.5, 34149, Trieste, Italy
| | - Giovanni Vinai
- Istituto Officina dei Materiali (IOM), CNR, Laboratorio TASC, Area Science Park, S.S. 14 km 163.5, 34149, Trieste, Italy
| | - Piero Torelli
- Istituto Officina dei Materiali (IOM), CNR, Laboratorio TASC, Area Science Park, S.S. 14 km 163.5, 34149, Trieste, Italy
| | - Agnese Magnani
- Department of Biotechnology, Chemistry and Pharmacy and INSTM Research Unit, University of Siena, Via Aldo Moro 2, 53100, Siena, Italy
| | - Roberta Sessoli
- Department of Chemistry "Ugo Schiff" and INSTM Research Unit, University of Florence, Via della Lastruccia 3-13, 50019, Sesto Fiorentino, Italy
| | - Stefano Menichetti
- Department of Chemistry "Ugo Schiff" and INSTM Research Unit, University of Florence, Via della Lastruccia 3-13, 50019, Sesto Fiorentino, Italy
| | - Lorenzo Sorace
- Department of Chemistry "Ugo Schiff" and INSTM Research Unit, University of Florence, Via della Lastruccia 3-13, 50019, Sesto Fiorentino, Italy
| | - Caterina Viglianisi
- Department of Chemistry "Ugo Schiff" and INSTM Research Unit, University of Florence, Via della Lastruccia 3-13, 50019, Sesto Fiorentino, Italy
| | - Matteo Mannini
- Department of Chemistry "Ugo Schiff" and INSTM Research Unit, University of Florence, Via della Lastruccia 3-13, 50019, Sesto Fiorentino, Italy
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12
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Shi Y, Wang L, Wang Z, Vinai G, Braglia L, Torelli P, Aruta C, Traversa E, Liu W, Yang N. Defect Engineering for Tuning the Photoresponse of Ceria-Based Solid Oxide Photoelectrochemical Cells. ACS Appl Mater Interfaces 2021; 13:541-551. [PMID: 33373206 DOI: 10.1021/acsami.0c17921] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Solid oxide photoelectrochemical cells (SOPECs) with inorganic ion-conducting electrolytes provide an alternative solution for light harvesting and conversion. Exploring potential photoelectrodes for SOPECs and understanding their operation mechanisms are crucial for continuously developing this technology. Here, ceria-based thin films were newly explored as photoelectrodes for SOPEC applications. It was found that the photoresponse of ceria-based thin films can be tuned both by Sm-doping-induced defects and by the heating temperature of SOPECs. The whole process was found to depend on the surface electrochemical redox reactions synergistically with the bulk photoelectric effect. Samarium doping level can selectively switch the open-circuit voltages polarity of SOPECs under illumination, thus shifting the potential of photoelectrodes and changing their photoresponse. The role of defect chemistry engineering in determining such a photoelectrochemical process was discussed. Transient absorption and X-ray photoemission spectroscopies, together with the state-of-the-art in operando X-ray absorption spectroscopy, allowed us to provide a compelling explanation of the experimentally observed switching behavior on the basis of the surface reactions and successive charge balance in the bulk.
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Affiliation(s)
- Yanuo Shi
- Electrochemical Thin Film Group, School of Physical Science and Technology, ShanghaiTech University, Shanghai, P.R. China
| | - Luyao Wang
- Electrochemical Thin Film Group, School of Physical Science and Technology, ShanghaiTech University, Shanghai, P.R. China
| | - Ziyu Wang
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, P.R. China
| | - Giovanni Vinai
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, Area Science Park, S.S. 14 km 163.5, Trieste I-34149, Italy
| | - Luca Braglia
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, Area Science Park, S.S. 14 km 163.5, Trieste I-34149, Italy
| | - Piero Torelli
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, Area Science Park, S.S. 14 km 163.5, Trieste I-34149, Italy
| | - Carmela Aruta
- CNR-SPIN, c/o Università di Roma Tor Vergata, Via del Politecnico, 1 Rome 00133, Italy
| | - Enrico Traversa
- School of Materials and Energy, University of Electronic Science and Technology of China, 2006 Xiyuan Road, Chengdu, Sichuan 611731, P.R. China
| | - Weimin Liu
- School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, P.R. China
| | - Nan Yang
- Electrochemical Thin Film Group, School of Physical Science and Technology, ShanghaiTech University, Shanghai, P.R. China
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13
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Vinai G. SP-0143: For the motion: Hippocampal Avoidance: Proving Causation from Bench to Bedside to Beam. Radiother Oncol 2020. [DOI: 10.1016/s0167-8140(21)00167-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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14
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Yang N, Knez D, Vinai G, Torelli P, Ciancio R, Orgiani P, Aruta C. Improved Structural Properties in Homogeneously Doped Sm 0.4Ce 0.6O 2-δ Epitaxial Thin Films: High Doping Effect on the Electronic Bands. ACS Appl Mater Interfaces 2020; 12:47556-47563. [PMID: 32985188 DOI: 10.1021/acsami.0c13495] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The study of ionic materials on nanometer scale is of great relevance for efficient miniaturized devices for energy applications. The epitaxial growth of thin films can be a valid route to tune the properties of the materials and thus obtain new degrees of freedom in materials design. High crystal quality SmxCe1-xO2-δ films are here reported at a high doping level up to x = 0.4, thanks to the good lattice matching with the (110) oriented NdGaO3 substrate. X-ray diffraction and transmission electron microscopy demonstrate the ordered structural quality and absence of Sm segregation at the macroscopic and atomic level, respectively. Therefore, in epitaxial thin films, the homogeneous doping can be obtained even with the high dopant content not always approachable in bulk form, getting even an improvement of the structural properties. In situ spectroscopic measurements by X-ray photoemission and X-ray absorption show the O 2p band shift toward the Fermi level, which can favor the oxygen exchange and vacancy formation on the surface when the Sm doping is increased to x = 0.4. X-ray absorption spectroscopy also confirms the absence of ordered oxygen vacancy clusters and further reveals that the 5d eg and t2g states are well separated by the crystal field in the undistorted local structure even in the case of a high doping level up to x = 0.4.
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Affiliation(s)
- Nan Yang
- School of Physical Science and Technology, ShanghaiTech University, 201210 Shanghai, China
| | - Daniel Knez
- CNR-IOM, TASC National Laboratory, I-34149 Trieste, Italy
| | - Giovanni Vinai
- CNR-IOM, TASC National Laboratory, I-34149 Trieste, Italy
| | - Piero Torelli
- CNR-IOM, TASC National Laboratory, I-34149 Trieste, Italy
| | - Regina Ciancio
- CNR-IOM, TASC National Laboratory, I-34149 Trieste, Italy
| | - Pasquale Orgiani
- CNR-IOM, TASC National Laboratory, I-34149 Trieste, Italy
- CNR-SPIN c/o University of Salerno, I-84084 Fisciano, Italy
| | - Carmela Aruta
- CNR-SPIN c/o University of Roma Tor Vergata, I-00133 Rome, Italy
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15
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Zhang L, Yang T, He X, Zhang W, Vinai G, Tang CS, Yin X, Torelli P, Feng YP, Wong PKJ, Wee ATS. Molecular Beam Epitaxy of Two-Dimensional Vanadium-Molybdenum Diselenide Alloys. ACS Nano 2020; 14:11140-11149. [PMID: 32794699 DOI: 10.1021/acsnano.0c02124] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Two-dimensional (2D) alloys represent a versatile platform that extends the properties of atomically thin transition-metal dichalcogenides. Here, using molecular beam epitaxy, we investigate the growth of 2D vanadium-molybdenum diselenide alloys, VxMo1-xSe2, on highly oriented pyrolytic graphite and unveil their structural, chemical, and electronic integrities via measurements by scanning tunneling microscopy/spectroscopy, synchrotron X-ray photoemission, and X-ray absorption spectroscopy (XAS). Essentially, we found a critical value of x = ∼0.44, below which phase separation occurs and above which a homogeneous metallic phase is favored. Another observation is an effective increase in the density of mirror twin boundaries of constituting MoSe2 in the low V concentration regime (x ≤ 0.05). Density functional theory calculations support our experimental results on the thermal stability of 2D VxMo1-xSe2 alloys and suggest an H phase of the homogeneous alloys with alternating parallel V and Mo strips randomly in-plane stacked. Element-specific XAS of the 2D alloys, which clearly indicates quenched atomic multiplets similar to the case of 2H-VSe2, provides strong evidence for the H phase of the 2D alloys. This work provides a comprehensive understanding of the thermal stability, chemical state, and electronic structure of 2D VxMo1-xSe2 alloys, useful for the future design of 2D electronic devices.
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Affiliation(s)
- Lei Zhang
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542, Singapore
- Centre for Advanced 2D Materials (CA2DM) and Graphene Research Centre (GRC), National University of Singapore, 6 Science Drive 2, Singapore 117546, Singapore
| | - Tong Yang
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542, Singapore
| | - Xiaoyue He
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542, Singapore
- Songshan Lake Materials Laboratory, Dongguan 523808, China
| | - Wen Zhang
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542, Singapore
- School of Electronics and Information, Northwestern Polytechnical University, Xi'an 710072, P.R. China
| | - Giovanni Vinai
- Instituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, Area Science Park, S.S. km 163.5, Trieste I-34149, Italy
| | - Chi Sin Tang
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542, Singapore
- NUS Graduate School for Integrative Sciences and Engineering, National University of Singapore, Singapore 117456, Singapore
| | - Xinmao Yin
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542, Singapore
- Singapore Synchrotron Light Source (SSLS), National University of Singapore, 5 Research Link, Singapore 117603, Singapore
| | - Piero Torelli
- Instituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, Area Science Park, S.S. km 163.5, Trieste I-34149, Italy
| | - Yuan Ping Feng
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542, Singapore
| | - Ping Kwan Johnny Wong
- Centre for Advanced 2D Materials (CA2DM) and Graphene Research Centre (GRC), National University of Singapore, 6 Science Drive 2, Singapore 117546, Singapore
- School of Electronics and Information, Northwestern Polytechnical University, Xi'an 710072, P.R. China
| | - Andrew T S Wee
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542, Singapore
- Centre for Advanced 2D Materials (CA2DM) and Graphene Research Centre (GRC), National University of Singapore, 6 Science Drive 2, Singapore 117546, Singapore
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16
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Vinai G, Motti F, Petrov AY, Polewczyk V, Bonanni V, Edla R, Gobaut B, Fujii J, Suran F, Benedetti D, Salvador F, Fondacaro A, Rossi G, Panaccione G, Davidson BA, Torelli P. An integrated ultra-high vacuum apparatus for growth and in situ characterization of complex materials. Rev Sci Instrum 2020; 91:085109. [PMID: 32872955 DOI: 10.1063/5.0005302] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Accepted: 07/29/2020] [Indexed: 06/11/2023]
Abstract
Here, we present an integrated ultra-high vacuum apparatus-named MBE-Cluster -dedicated to the growth and in situ structural, spectroscopic, and magnetic characterization of complex materials. Molecular Beam Epitaxy (MBE) growth of metal oxides, e.g., manganites, and deposition of the patterned metallic layers can be fabricated and in situ characterized by reflection high-energy electron diffraction, low-energy electron diffraction, Auger electron spectroscopy, x-ray photoemission spectroscopy, and azimuthal longitudinal magneto-optic Kerr effect. The temperature can be controlled in the range from 5 K to 580 K, with the possibility of application of magnetic fields H up to ±7 kOe and electric fields E for voltages up to ±500 V. The MBE-Cluster operates for in-house research as well as user facility in combination with the APE beamlines at Sincrotrone-Trieste and the high harmonic generator facility for time-resolved spectroscopy.
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Affiliation(s)
- G Vinai
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, Area Science Park, S.S. 14 Km 163.5, Trieste I-34149, Italy
| | - F Motti
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, Area Science Park, S.S. 14 Km 163.5, Trieste I-34149, Italy
| | - A Yu Petrov
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, Area Science Park, S.S. 14 Km 163.5, Trieste I-34149, Italy
| | - V Polewczyk
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, Area Science Park, S.S. 14 Km 163.5, Trieste I-34149, Italy
| | - V Bonanni
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, Area Science Park, S.S. 14 Km 163.5, Trieste I-34149, Italy
| | - R Edla
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, Area Science Park, S.S. 14 Km 163.5, Trieste I-34149, Italy
| | - B Gobaut
- Elettra-Sincrotrone Trieste S.C.p.A, Area Science Park, 34149 Basovizza, Trieste, Italy
| | - J Fujii
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, Area Science Park, S.S. 14 Km 163.5, Trieste I-34149, Italy
| | - F Suran
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, Area Science Park, S.S. 14 Km 163.5, Trieste I-34149, Italy
| | - D Benedetti
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, Area Science Park, S.S. 14 Km 163.5, Trieste I-34149, Italy
| | - F Salvador
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, Area Science Park, S.S. 14 Km 163.5, Trieste I-34149, Italy
| | - A Fondacaro
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, Area Science Park, S.S. 14 Km 163.5, Trieste I-34149, Italy
| | - G Rossi
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, Area Science Park, S.S. 14 Km 163.5, Trieste I-34149, Italy
| | - G Panaccione
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, Area Science Park, S.S. 14 Km 163.5, Trieste I-34149, Italy
| | - B A Davidson
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, Area Science Park, S.S. 14 Km 163.5, Trieste I-34149, Italy
| | - P Torelli
- Istituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, Area Science Park, S.S. 14 Km 163.5, Trieste I-34149, Italy
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17
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Zhang W, Zhang L, Wong PKJ, Yuan J, Vinai G, Torelli P, van der Laan G, Feng YP, Wee ATS. Magnetic Transition in Monolayer VSe 2 via Interface Hybridization. ACS Nano 2019; 13:8997-9004. [PMID: 31306576 DOI: 10.1021/acsnano.9b02996] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Magnetism in monolayer (ML) VSe2 has attracted broad interest in spintronics, while existing reports have not reached consensus. Using element-specific X-ray magnetic circular dichroism, a magnetic transition in ML VSe2 has been demonstrated at the contamination-free interface between Co and VSe2. Through interfacial hybridization with a Co atomic overlayer, a magnetic moment of about 0.4 μB per V atom in ML VSe2 is revealed, approaching values predicted by previous theoretical calculations. Promotion of the ferromagnetism in ML VSe2 is accompanied by its antiferromagnetic coupling to Co and a reduction in the spin moment of Co. In comparison to the absence of this interface-induced ferromagnetism at the Fe/ML MoSe2 interface, these findings at the Co/ML VSe2 interface provide clear proof that the ML VSe2, initially with magnetic disorder, is on the verge of magnetic transition.
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Affiliation(s)
- Wen Zhang
- Department of Physics , National University of Singapore , 2 Science Drive 3 , Singapore 117542
| | - Lei Zhang
- Department of Physics , National University of Singapore , 2 Science Drive 3 , Singapore 117542
| | - Ping Kwan Johnny Wong
- Centre for Advanced 2D Materials and Graphene Research Centre , National University of Singapore , 6 Science Drive 2 , Singapore 117546
| | - Jiaren Yuan
- Department of Physics , National University of Singapore , 2 Science Drive 3 , Singapore 117542
| | - Giovanni Vinai
- Laboratorio TASC , IOM-CNR , S.S. 14 km 163.5, Basovizza , 34149 Trieste , Italy
| | - Piero Torelli
- Laboratorio TASC , IOM-CNR , S.S. 14 km 163.5, Basovizza , 34149 Trieste , Italy
| | - Gerrit van der Laan
- Magnetic Spectroscopy Group , Diamond Light Source , Didcot OX11 0DE , United Kingdom
| | - Yuan Ping Feng
- Department of Physics , National University of Singapore , 2 Science Drive 3 , Singapore 117542
| | - Andrew T S Wee
- Department of Physics , National University of Singapore , 2 Science Drive 3 , Singapore 117542
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18
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Wong PKJ, Zhang W, Bussolotti F, Yin X, Herng TS, Zhang L, Huang YL, Vinai G, Krishnamurthi S, Bukhvalov DW, Zheng YJ, Chua R, N'Diaye AT, Morton SA, Yang CY, Ou Yang KH, Torelli P, Chen W, Goh KEJ, Ding J, Lin MT, Brocks G, de Jong MP, Castro Neto AH, Wee ATS. Evidence of Spin Frustration in a Vanadium Diselenide Monolayer Magnet. Adv Mater 2019; 31:e1901185. [PMID: 30997712 DOI: 10.1002/adma.201901185] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Revised: 03/30/2019] [Indexed: 06/09/2023]
Abstract
Monolayer VSe2 , featuring both charge density wave and magnetism phenomena, represents a unique van der Waals magnet in the family of metallic 2D transition-metal dichalcogenides (2D-TMDs). Herein, by means of in situ microscopy and spectroscopic techniques, including scanning tunneling microscopy/spectroscopy, synchrotron X-ray and angle-resolved photoemission, and X-ray absorption, direct spectroscopic signatures are established, that identify the metallic 1T-phase and vanadium 3d1 electronic configuration in monolayer VSe2 grown on graphite by molecular-beam epitaxy. Element-specific X-ray magnetic circular dichroism, complemented with magnetic susceptibility measurements, further reveals monolayer VSe2 as a frustrated magnet, with its spins exhibiting subtle correlations, albeit in the absence of a long-range magnetic order down to 2 K and up to a 7 T magnetic field. This observation is attributed to the relative stability of the ferromagnetic and antiferromagnetic ground states, arising from its atomic-scale structural features, such as rotational disorders and edges. The results of this study extend the current understanding of metallic 2D-TMDs in the search for exotic low-dimensional quantum phenomena, and stimulate further theoretical and experimental studies on van der Waals monolayer magnets.
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Affiliation(s)
- Ping Kwan Johnny Wong
- Centre for Advanced 2D Materials (CA2DM) and Graphene Research Centre (GRC), National University of Singapore, 6 Science Drive 2, Singapore, 117546, Singapore
| | - Wen Zhang
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore, 117542, Singapore
| | - Fabio Bussolotti
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*Star), 2 Fusionopolis Way, Innovis, Singapore, 138634, Singapore
| | - Xinmao Yin
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore, 117542, Singapore
| | - Tun Seng Herng
- Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore, 117575, Singapore
| | - Lei Zhang
- Centre for Advanced 2D Materials (CA2DM) and Graphene Research Centre (GRC), National University of Singapore, 6 Science Drive 2, Singapore, 117546, Singapore
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore, 117542, Singapore
| | - Yu Li Huang
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore, 117542, Singapore
| | - Giovanni Vinai
- Instituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, Area Science Park, S.S. Km 163.5, Trieste, I-34149, Italy
| | - Sridevi Krishnamurthi
- Computational Materials Science, Faculty of Science and Technology and MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500, AE, Enschede, The Netherlands
| | - Danil W Bukhvalov
- College of Science, Institute of Materials Physics and Chemistry, Nanjing Forestry University, Nanjing, 210037, P. R. China
- Institute of Physics and Technology, Ural Federal University, Mira Street 19, 620002, Yekaterinburg, Russia
| | - Yu Jie Zheng
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore, 117542, Singapore
| | - Rebekah Chua
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore, 117542, Singapore
| | - Alpha T N'Diaye
- Advanced Light Source (ALS), Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Simon A Morton
- Advanced Light Source (ALS), Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Chao-Yao Yang
- Department of Physics, National Taiwan University, Taipei, 10617, Taiwan
| | - Kui-Hon Ou Yang
- Department of Physics, National Taiwan University, Taipei, 10617, Taiwan
| | - Piero Torelli
- Instituto Officina dei Materiali (IOM)-CNR, Laboratorio TASC, Area Science Park, S.S. Km 163.5, Trieste, I-34149, Italy
| | - Wei Chen
- Centre for Advanced 2D Materials (CA2DM) and Graphene Research Centre (GRC), National University of Singapore, 6 Science Drive 2, Singapore, 117546, Singapore
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore, 117542, Singapore
- Department of Chemistry, National University of Singapore, 2 Science Drive 3, Singapore, 117542, Singapore
| | - Kuan Eng Johnson Goh
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore, 117542, Singapore
- Institute of Materials Research and Engineering (IMRE), Agency for Science, Technology and Research (A*Star), 2 Fusionopolis Way, Innovis, Singapore, 138634, Singapore
| | - Jun Ding
- Department of Materials Science and Engineering, National University of Singapore, 9 Engineering Drive 1, Singapore, 117575, Singapore
| | - Minn-Tsong Lin
- Department of Physics, National Taiwan University, Taipei, 10617, Taiwan
| | - Geert Brocks
- Computational Materials Science, Faculty of Science and Technology and MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500, AE, Enschede, The Netherlands
| | - Michel P de Jong
- NanoElectronics Group, MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500, AE, Enschede, The Netherlands
| | - Antonio H Castro Neto
- Centre for Advanced 2D Materials (CA2DM) and Graphene Research Centre (GRC), National University of Singapore, 6 Science Drive 2, Singapore, 117546, Singapore
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore, 117542, Singapore
| | - Andrew Thye Shen Wee
- Centre for Advanced 2D Materials (CA2DM) and Graphene Research Centre (GRC), National University of Singapore, 6 Science Drive 2, Singapore, 117546, Singapore
- Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore, 117542, Singapore
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19
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Brambilla A, Picone A, Giannotti D, Calloni A, Berti G, Bussetti G, Achilli S, Fratesi G, Trioni MI, Vinai G, Torelli P, Panaccione G, Duò L, Finazzi M, Ciccacci F. Correction to "Enhanced Magnetic Hybridization of a Spinterface through Insertion of a Two-Dimensional Magnetic Oxide Layer". Nano Lett 2019; 19:2186. [PMID: 30758211 DOI: 10.1021/acs.nanolett.9b00190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
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20
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Rinaldi C, Varotto S, Asa M, Sławińska J, Fujii J, Vinai G, Cecchi S, Di Sante D, Calarco R, Vobornik I, Panaccione G, Picozzi S, Bertacco R. Ferroelectric Control of the Spin Texture in GeTe. Nano Lett 2018; 18:2751-2758. [PMID: 29380606 PMCID: PMC6994063 DOI: 10.1021/acs.nanolett.7b04829] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Revised: 01/20/2018] [Indexed: 05/27/2023]
Abstract
The electric and nonvolatile control of the spin texture in semiconductors would represent a fundamental step toward novel electronic devices combining memory and computing functionalities. Recently, GeTe has been theoretically proposed as the father compound of a new class of materials, namely ferroelectric Rashba semiconductors. They display bulk bands with giant Rashba-like splitting due to the inversion symmetry breaking arising from the ferroelectric polarization, thus allowing for the ferroelectric control of the spin. Here, we provide the experimental demonstration of the correlation between ferroelectricity and spin texture. A surface-engineering strategy is used to set two opposite predefined uniform ferroelectric polarizations, inward and outward, as monitored by piezoresponse force microscopy. Spin and angular resolved photoemission experiments show that these GeTe(111) surfaces display opposite sense of circulation of spin in bulk Rashba bands. Furthermore, we demonstrate the crafting of nonvolatile ferroelectric patterns in GeTe films at the nanoscale by using the conductive tip of an atomic force microscope. Based on the intimate link between ferroelectric polarization and spin in GeTe, ferroelectric patterning paves the way to the investigation of devices with engineered spin configurations.
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Affiliation(s)
- Christian Rinaldi
- Department
of Physics, Politecnico di Milano, 20133 Milano, Italy
- IFN-CNR,
Politecnico di Milano, 20133 Milano, Italy
| | - Sara Varotto
- Department
of Physics, Politecnico di Milano, 20133 Milano, Italy
| | - Marco Asa
- Department
of Physics, Politecnico di Milano, 20133 Milano, Italy
| | - Jagoda Sławińska
- Consiglio
Nazionale delle Ricerche CNR-SPIN, Sede
Temporanea di Chieti, c/o Univ. “G. D’Annunzio”, 66100 Chieti, Italy
| | - Jun Fujii
- CNR-IOM, Laboratorio TASC in Area Science
Park - Basovizza, 34149 Trieste, Italy
| | - Giovanni Vinai
- CNR-IOM, Laboratorio TASC in Area Science
Park - Basovizza, 34149 Trieste, Italy
| | - Stefano Cecchi
- Paul-Drude-Institut
für Festkörperelektronik, Hausvogteiplatz 5-7, 10117 Berlin, Germany
| | - Domenico Di Sante
- Institut
für Theoretische Physik und Astrophysik, Universität
Würzburg, Am Hubland
Campus Süd, Würzburg 97074, Germany
| | - Raffaella Calarco
- Paul-Drude-Institut
für Festkörperelektronik, Hausvogteiplatz 5-7, 10117 Berlin, Germany
| | - Ivana Vobornik
- CNR-IOM, Laboratorio TASC in Area Science
Park - Basovizza, 34149 Trieste, Italy
| | - Giancarlo Panaccione
- CNR-IOM, Laboratorio TASC in Area Science
Park - Basovizza, 34149 Trieste, Italy
| | - Silvia Picozzi
- Consiglio
Nazionale delle Ricerche CNR-SPIN, Sede
Temporanea di Chieti, c/o Univ. “G. D’Annunzio”, 66100 Chieti, Italy
| | - Riccardo Bertacco
- Department
of Physics, Politecnico di Milano, 20133 Milano, Italy
- IFN-CNR,
Politecnico di Milano, 20133 Milano, Italy
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21
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Vinai G, Ressel B, Torelli P, Loi F, Gobaut B, Ciancio R, Casarin B, Caretta A, Capasso L, Parmigiani F, Cugini F, Solzi M, Malvestuto M, Ciprian R. Giant magneto-electric coupling in 100 nm thick Co capped by ZnO nanorods. Nanoscale 2018; 10:1326-1336. [PMID: 29296985 DOI: 10.1039/c7nr09233d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Here we report a giant, completely reversible magneto-electric coupling of 100 nm polycrystalline Co layer in contact with ZnO nanorods. When the sample is under an applied bias of ±2 V, the Co magnetic coercivity is reduced by a factor 5 from the un-poled case, with additionally a reduction of total magnetic moment in Co. Taking into account the chemical properties of ZnO nanorods measured by X-rays absorption near edge spectroscopy under bias, we conclude that these macroscopic effects on the magnetic response of the Co layer are due to the microstructure and the strong strain-driven magneto-electric coupling induced by the ZnO nanorods, whose nanostructuration maximizes the piezoelectric response under bias.
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Affiliation(s)
- Giovanni Vinai
- CNR-Istituto Officina dei Materiali IOM, s.s. 14 km 163.5, 34149, Trieste, Italy
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22
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Brambilla A, Picone A, Giannotti D, Calloni A, Berti G, Bussetti G, Achilli S, Fratesi G, Trioni MI, Vinai G, Torelli P, Panaccione G, Duò L, Finazzi M, Ciccacci F. Enhanced Magnetic Hybridization of a Spinterface through Insertion of a Two-Dimensional Magnetic Oxide Layer. Nano Lett 2017; 17:7440-7446. [PMID: 29149565 DOI: 10.1021/acs.nanolett.7b03314] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Interfaces between organic semiconductors and ferromagnetic metals offer intriguing opportunities in the rapidly developing field of organic spintronics. Understanding and controlling the spin-polarized electronic states at the interface is the key toward a reliable exploitation of this kind of systems. Here we propose an approach consisting in the insertion of a two-dimensional magnetic oxide layer at the interface with the aim of both increasing the reproducibility of the interface preparation and offering a way for a further fine control over the electronic and magnetic properties. We have inserted a two-dimensional Cr4O5 layer at the C60/Fe(001) interface and have characterized the corresponding morphological, electronic, and magnetic properties. Scanning tunneling microscopy and electron diffraction show that the film grows well-ordered both in the monolayer and multilayer regimes. Electron spectroscopies confirm that hybridization of the electronic states occurs at the interface. Finally, magnetic dichroism in X-ray absorption shows an unprecedented spin-polarization of the hybridized fullerene states. The latter result is discussed also in light of an ab initio theoretical analysis.
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Affiliation(s)
- Alberto Brambilla
- Dipartimento di Fisica, Politecnico di Milano , piazza Leonardo da Vinci, 32, 20133 Milano, Italy
| | - Andrea Picone
- Dipartimento di Fisica, Politecnico di Milano , piazza Leonardo da Vinci, 32, 20133 Milano, Italy
| | - Dario Giannotti
- Dipartimento di Fisica, Politecnico di Milano , piazza Leonardo da Vinci, 32, 20133 Milano, Italy
| | - Alberto Calloni
- Dipartimento di Fisica, Politecnico di Milano , piazza Leonardo da Vinci, 32, 20133 Milano, Italy
| | - Giulia Berti
- Dipartimento di Fisica, Politecnico di Milano , piazza Leonardo da Vinci, 32, 20133 Milano, Italy
| | - Gianlorenzo Bussetti
- Dipartimento di Fisica, Politecnico di Milano , piazza Leonardo da Vinci, 32, 20133 Milano, Italy
| | - Simona Achilli
- Dipartimento di Fisica, Università degli Studi di Milano , Via Celoria, 16, 20133 Milano, Italy
| | - Guido Fratesi
- Dipartimento di Fisica, Università degli Studi di Milano , Via Celoria, 16, 20133 Milano, Italy
| | - Mario I Trioni
- CNR - National Research Council of Italy, ISTM , via Golgi 19, 20133 Milano, Italy
| | - Giovanni Vinai
- Laboratorio TASC, IOM-CNR , S.S. 14 km 163.5, Basovizza, I, 34149 Trieste, Italy
| | - Piero Torelli
- Laboratorio TASC, IOM-CNR , S.S. 14 km 163.5, Basovizza, I, 34149 Trieste, Italy
| | - Giancarlo Panaccione
- Laboratorio TASC, IOM-CNR , S.S. 14 km 163.5, Basovizza, I, 34149 Trieste, Italy
| | - Lamberto Duò
- Dipartimento di Fisica, Politecnico di Milano , piazza Leonardo da Vinci, 32, 20133 Milano, Italy
| | - Marco Finazzi
- Dipartimento di Fisica, Politecnico di Milano , piazza Leonardo da Vinci, 32, 20133 Milano, Italy
| | - Franco Ciccacci
- Dipartimento di Fisica, Politecnico di Milano , piazza Leonardo da Vinci, 32, 20133 Milano, Italy
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23
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Pincelli T, Lollobrigida V, Borgatti F, Regoutz A, Gobaut B, Schlueter C, Lee TL, Payne DJ, Oura M, Tamasaku K, Petrov AY, Graziosi P, Granozio FM, Cavallini M, Vinai G, Ciprian R, Back CH, Rossi G, Taguchi M, Daimon H, van der Laan G, Panaccione G. Quantifying the critical thickness of electron hybridization in spintronics materials. Nat Commun 2017; 8:16051. [PMID: 28714466 PMCID: PMC5520016 DOI: 10.1038/ncomms16051] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Accepted: 05/15/2017] [Indexed: 11/09/2022] Open
Abstract
In the rapidly growing field of spintronics, simultaneous control of electronic and magnetic properties is essential, and the perspective of building novel phases is directly linked to the control of tuning parameters, for example, thickness and doping. Looking at the relevant effects in interface-driven spintronics, the reduced symmetry at a surface and interface corresponds to a severe modification of the overlap of electron orbitals, that is, to a change of electron hybridization. Here we report a chemically and magnetically sensitive depth-dependent analysis of two paradigmatic systems, namely La1−xSrxMnO3 and (Ga,Mn)As. Supported by cluster calculations, we find a crossover between surface and bulk in the electron hybridization/correlation and we identify a spectroscopic fingerprint of bulk metallic character and ferromagnetism versus depth. The critical thickness and the gradient of hybridization are measured, setting an intrinsic limit of 3 and 10 unit cells from the surface, respectively, for (Ga,Mn)As and La1−xSrxMnO3, for fully restoring bulk properties. Surface versus bulk effects in electronic structure of spintronics materials are crucial to their applications but are yet well understood. Here the authors experimentally determine the critical thickness that defines the crossover of electron hybridization between surface and bulk for two prototype spintronics materials.
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Affiliation(s)
- T Pincelli
- Istituto Officina dei Materiali-CNR, Laboratorio TASC, Area Science Park, S.S. 14, Km 163.5, Trieste I-34149, Italy.,Dipartimento di Fisica, Università di Milano, Via Celoria 16, Milano I-20133, Italy
| | - V Lollobrigida
- Istituto Officina dei Materiali-CNR, Laboratorio TASC, Area Science Park, S.S. 14, Km 163.5, Trieste I-34149, Italy.,Dipartimento di Scienze, Università degli Studi Roma Tre, Via della Vasca Navale 84, Roma I-00146, Italy
| | - F Borgatti
- Consiglio Nazionale delle Ricerche-Istituto per lo Studio dei Materiali Nanostrutturati (CNR-ISMN), via P. Gobetti 101, Bologna I-40129, Italy
| | - A Regoutz
- Department of Materials, Imperial College London, South Kensington, London SW7 2AZ, UK
| | - B Gobaut
- Sincrotrone Trieste S.C.p.A., S.S. 14 Km 163.5, Area Science Park, Trieste 34149, Italy
| | - C Schlueter
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, UK
| | - T-L Lee
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, UK
| | - D J Payne
- Department of Materials, Imperial College London, South Kensington, London SW7 2AZ, UK
| | - M Oura
- RIKEN SPring-8 Center, Kouto 1-1-1, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
| | - K Tamasaku
- RIKEN SPring-8 Center, Kouto 1-1-1, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
| | - A Y Petrov
- Istituto Officina dei Materiali-CNR, Laboratorio TASC, Area Science Park, S.S. 14, Km 163.5, Trieste I-34149, Italy
| | - P Graziosi
- Consiglio Nazionale delle Ricerche-Istituto per lo Studio dei Materiali Nanostrutturati (CNR-ISMN), via P. Gobetti 101, Bologna I-40129, Italy
| | - F Miletto Granozio
- CNR-SPIN, Complesso Universitario Monte S. Angelo, Napoli 80126, Italy.,Dipartimento di Fisica, Università 'Federico II' di Napoli, Napoli, 80126, Italy
| | - M Cavallini
- Consiglio Nazionale delle Ricerche-Istituto per lo Studio dei Materiali Nanostrutturati (CNR-ISMN), via P. Gobetti 101, Bologna I-40129, Italy
| | - G Vinai
- Istituto Officina dei Materiali-CNR, Laboratorio TASC, Area Science Park, S.S. 14, Km 163.5, Trieste I-34149, Italy
| | - R Ciprian
- Istituto Officina dei Materiali-CNR, Laboratorio TASC, Area Science Park, S.S. 14, Km 163.5, Trieste I-34149, Italy
| | - C H Back
- Institut fur Experimentelle Physik, Universitat Regensburg, Regensburg D-93040, Germany
| | - G Rossi
- Istituto Officina dei Materiali-CNR, Laboratorio TASC, Area Science Park, S.S. 14, Km 163.5, Trieste I-34149, Italy.,Dipartimento di Fisica, Università di Milano, Via Celoria 16, Milano I-20133, Italy
| | - M Taguchi
- RIKEN SPring-8 Center, Kouto 1-1-1, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan.,Nara Institute of Science and Technology, 8-9165 Takayama, Ikoma, Nara 630-0192, Japan
| | - H Daimon
- Nara Institute of Science and Technology, 8-9165 Takayama, Ikoma, Nara 630-0192, Japan
| | - G van der Laan
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot OX11 0DE, UK
| | - G Panaccione
- Istituto Officina dei Materiali-CNR, Laboratorio TASC, Area Science Park, S.S. 14, Km 163.5, Trieste I-34149, Italy
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24
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Benedetti S, Valenti I, di Bona A, Vinai G, Castan-Guerrero C, Valeri S, Catellani A, Ruini A, Torelli P, Calzolari A. Spectroscopic identification of the chemical interplay between defects and dopants in Al-doped ZnO. Phys Chem Chem Phys 2017; 19:29364-29371. [DOI: 10.1039/c7cp05864k] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Contributions to the spectroscopic response of defects and dopants in Al-doped ZnO films are determined combining X-ray spectroscopies and DFT.
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Ciprian R, Baratto C, Giglia A, Koshmak K, Vinai G, Donarelli M, Ferroni M, Campanini M, Comini E, Ponzoni A, Sberveglieri G. Magnetic gas sensing exploiting the magneto-optical Kerr effect on ZnO nanorods/Co layer system. RSC Adv 2016. [DOI: 10.1039/c6ra00522e] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
A new system based on a Co film covered by ZnO nanorods has been fabricated with sputtering technique. It represents a promising candidate for future generation of magnetic gas sensing devices.
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Ciprian R, Torelli P, Giglia A, Gobaut B, Ressel B, Vinai G, Stupar M, Caretta A, De Ninno G, Pincelli T, Casarin B, Adhikary G, Sberveglieri G, Baratto C, Malvestuto M. New strategy for magnetic gas sensing. RSC Adv 2016. [DOI: 10.1039/c6ra18213e] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
New strategy for room temperature magnetic gas sensing based on magnetoelectrically-coupled hybrids. The sensor is sensitive, fast and cost-effective. The sensing is allowed thanks to the magneto-electric coupling at the interface.
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Affiliation(s)
- R. Ciprian
- Elettra Sincrotrone di Trieste
- Trieste
- Italy
| | - P. Torelli
- CNR-Istituto Officina dei Materiali IOM
- Trieste
- Italy
| | - A. Giglia
- CNR-Istituto Officina dei Materiali IOM
- Trieste
- Italy
| | - B. Gobaut
- Elettra Sincrotrone di Trieste
- Trieste
- Italy
| | | | - G. Vinai
- CNR-Istituto Officina dei Materiali IOM
- Trieste
- Italy
| | | | - A. Caretta
- Elettra Sincrotrone di Trieste
- Trieste
- Italy
| | - G. De Ninno
- Elettra Sincrotrone di Trieste
- Trieste
- Italy
- University of Nova Gorica
- Slovenia
| | - T. Pincelli
- CNR-Istituto Officina dei Materiali IOM
- Trieste
- Italy
- Physics Department
- University of Milano
| | - B. Casarin
- Elettra Sincrotrone di Trieste
- Trieste
- Italy
- Physics Department
- University of Trieste
| | | | - G. Sberveglieri
- CNR-INO and Department of Information Engineering
- University of Brescia
- 25133 Brescia
- Italy
| | - C. Baratto
- CNR-INO and Department of Information Engineering
- University of Brescia
- 25133 Brescia
- Italy
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Vinai G, Moritz J, Gaudin G, Vogel J, Prejbeanu I, Dieny B. Focused Kerr measurements on patterned arrays of exchange biased square dots. EPJ Web of Conferences 2014. [DOI: 10.1051/epjconf/20147505003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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