1
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Curti L, Prado Y, Michel A, Talbot D, Baptiste B, Otero E, Ohresser P, Journaux Y, Cartier-Dit-Moulin C, Dupuis V, Fleury B, Sainctavit P, Arrio MA, Fresnais J, Lisnard L. Room-temperature-persistent magnetic interaction between coordination complexes and nanoparticles in maghemite-based nanohybrids. NANOSCALE 2024; 16:10607-10617. [PMID: 38758111 DOI: 10.1039/d4nr01220h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2024]
Abstract
Maghemite nanoparticles functionalised with Co(II) coordination complexes at their surface show a significant increase of their magnetic anisotropy, leading to a doubling of the blocking temperature and a sixfold increase of the coercive field. Magnetometric studies suggest an enhancement that is not related to surface disordering, and point to a molecular effect involving magnetic exchange interactions mediated by the oxygen atoms at the interface as its source. Field- and temperature-dependent X-ray absorption spectroscopy (XAS) and X-ray magnetic circular dichroism (XMCD) studies show that the magnetic anisotropy enhancement is not limited to surface atoms and involves the core of the nanoparticle. These studies also point to a mechanism driven by anisotropic exchange and confirm the strength of the magnetic exchange interactions. The coupling between the complex and the nanoparticle persists at room temperature. Simulations based on the XMCD data give an effective exchange field value through the oxido coordination bridge between the Co(II) complex and the nanoparticle that is comparable to the exchange field between iron ions in bulk maghemite. Further evidence of the effectiveness of the oxido coordination bridge in mediating the magnetic interaction at the interface is given with the Ni(II) analog to the Co(II) surface-functionalised nanoparticles. A substrate-induced magnetic response is observed for the Ni(II) complexes, up to room temperature.
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Affiliation(s)
- Leonardo Curti
- Sorbonne Université, CNRS, Institut Parisien de Chimie Moléculaire, IPCM, F-75005, Paris, France.
| | - Yoann Prado
- Sorbonne Université, CNRS, Laboratoire de Physicochimie des Électrolytes et Nanosystèmes interfaciaux, PHENIX, F-75005, France.
| | - Aude Michel
- Sorbonne Université, CNRS, Laboratoire de Physicochimie des Électrolytes et Nanosystèmes interfaciaux, PHENIX, F-75005, France.
| | - Delphine Talbot
- Sorbonne Université, CNRS, Laboratoire de Physicochimie des Électrolytes et Nanosystèmes interfaciaux, PHENIX, F-75005, France.
| | - Benoît Baptiste
- CNRS, Sorbonne Université, IRD, MNHN, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, IMPMC, F-75005, Paris, France.
| | - Edwige Otero
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette, France
| | - Philippe Ohresser
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette, France
| | - Yves Journaux
- Sorbonne Université, CNRS, Institut Parisien de Chimie Moléculaire, IPCM, F-75005, Paris, France.
| | | | - Vincent Dupuis
- Sorbonne Université, CNRS, Laboratoire de Physicochimie des Électrolytes et Nanosystèmes interfaciaux, PHENIX, F-75005, France.
| | - Benoit Fleury
- Sorbonne Université, CNRS, Institut Parisien de Chimie Moléculaire, IPCM, F-75005, Paris, France.
| | - Philippe Sainctavit
- CNRS, Sorbonne Université, IRD, MNHN, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, IMPMC, F-75005, Paris, France.
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette, France
| | - Marie-Anne Arrio
- CNRS, Sorbonne Université, IRD, MNHN, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, IMPMC, F-75005, Paris, France.
| | - Jérôme Fresnais
- Sorbonne Université, CNRS, Laboratoire de Physicochimie des Électrolytes et Nanosystèmes interfaciaux, PHENIX, F-75005, France.
| | - Laurent Lisnard
- Sorbonne Université, CNRS, Institut Parisien de Chimie Moléculaire, IPCM, F-75005, Paris, France.
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2
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Dunstan MA, Giansiracusa MJ, Calvello S, Sorace L, Krause-Heuer AM, Soncini A, Mole RA, Boskovic C. Ab initio-based determination of lanthanoid-radical exchange as visualised by inelastic neutron scattering. Chem Sci 2024; 15:4466-4477. [PMID: 38516080 PMCID: PMC10952085 DOI: 10.1039/d3sc04229d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 02/12/2024] [Indexed: 03/23/2024] Open
Abstract
Magnetic exchange coupling can modulate the slow magnetic relaxation in single-molecule magnets. Despite this, elucidation of exchange coupling remains a significant challenge for the lanthanoid(iii) ions, both experimentally and computationally. In this work, the crystal field splitting and 4f-π exchange coupling in the erbium-semiquinonate complex [ErTp2dbsq] (Er-dbsq; Tp- = hydro-tris(1-pyrazolyl)borate, dbsqH2 = 3,5-di-tert-butyl-1,2-semiquinone) have been determined by inelastic neutron scattering (INS), magnetometry, and CASSCF-SO ab initio calculations. A related complex with a diamagnetic ligand, [ErTp2trop] (Er-trop; tropH = tropolone), has been used as a model for the crystal field splitting in the absence of coupling. Magnetic and INS data indicate antiferromagnetic exchange for Er-dbsq with a coupling constant of Jex = -0.23 meV (-1.8 cm-1) (-2Jex formalism) and good agreement is found between theory and experiment, with the low energy magnetic and spectroscopic properties well modelled. Most notable is the ability of the ab initio modelling to reproduce the signature of interference between localised 4f states and delocalised π-radical states that is evident in the Q-dependence of the exchange excitation. This work highlights the power of combining INS with EPR and magnetometry for determination of ground state properties, as well as the enhanced capability of CASSCF-SO ab initio calculations and purposely developed ab initio-based theoretical models. We deliver an unprecedentedly detailed representation of the entangled character of 4f-π exchange states, which is obtained via an accurate image of the spin-orbital transition density between the 4f-π exchange coupled wavefunctions.
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Affiliation(s)
- Maja A Dunstan
- School of Chemistry, The University of Melbourne Parkville VIC 3010 Australia
| | | | - Simone Calvello
- School of Chemistry, The University of Melbourne Parkville VIC 3010 Australia
- Australian Nuclear Science and Technology Organisation, Locked Bag 2001 Kirrawee DC 2232 Australia
| | - Lorenzo Sorace
- INFN Sez. di Firenze, Department of Chemistry, "Ugo Schiff", Università Degli Studi Firenze Via Della Lastruccia, 13 50019 Sesto Fiorentino Italy
| | - Anwen M Krause-Heuer
- Australian Nuclear Science and Technology Organisation, Locked Bag 2001 Kirrawee DC 2232 Australia
| | - Alessandro Soncini
- School of Chemistry, The University of Melbourne Parkville VIC 3010 Australia
- Department of Chemical Sciences, University of Padova Via Marzolo 1 35131 Padova Italy
| | - Richard A Mole
- Australian Nuclear Science and Technology Organisation, Locked Bag 2001 Kirrawee DC 2232 Australia
| | - Colette Boskovic
- School of Chemistry, The University of Melbourne Parkville VIC 3010 Australia
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3
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Chiesa A, Santini P, Garlatti E, Luis F, Carretta S. Molecular nanomagnets: a viable path toward quantum information processing? REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2024; 87:034501. [PMID: 38314645 DOI: 10.1088/1361-6633/ad1f81] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 01/17/2024] [Indexed: 02/06/2024]
Abstract
Molecular nanomagnets (MNMs), molecules containing interacting spins, have been a playground for quantum mechanics. They are characterized by many accessible low-energy levels that can be exploited to store and process quantum information. This naturally opens the possibility of using them as qudits, thus enlarging the tools of quantum logic with respect to qubit-based architectures. These additional degrees of freedom recently prompted the proposal for encoding qubits with embedded quantum error correction (QEC) in single molecules. QEC is the holy grail of quantum computing and this qudit approach could circumvent the large overhead of physical qubits typical of standard multi-qubit codes. Another important strength of the molecular approach is the extremely high degree of control achieved in preparing complex supramolecular structures where individual qudits are linked preserving their individual properties and coherence. This is particularly relevant for building quantum simulators, controllable systems able to mimic the dynamics of other quantum objects. The use of MNMs for quantum information processing is a rapidly evolving field which still requires to be fully experimentally explored. The key issues to be settled are related to scaling up the number of qudits/qubits and their individual addressing. Several promising possibilities are being intensively explored, ranging from the use of single-molecule transistors or superconducting devices to optical readout techniques. Moreover, new tools from chemistry could be also at hand, like the chiral-induced spin selectivity. In this paper, we will review the present status of this interdisciplinary research field, discuss the open challenges and envisioned solution paths which could finally unleash the very large potential of molecular spins for quantum technologies.
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Affiliation(s)
- A Chiesa
- Dipartimento di Scienze Matematiche, Fisiche e Informatiche, Università di Parma, I-43124 Parma, Italy
- INFN-Sezione di Milano-Bicocca, Gruppo Collegato di Parma, 43124 Parma, Italy
- UdR Parma, INSTM, I-43124 Parma, Italy
| | - P Santini
- Dipartimento di Scienze Matematiche, Fisiche e Informatiche, Università di Parma, I-43124 Parma, Italy
- INFN-Sezione di Milano-Bicocca, Gruppo Collegato di Parma, 43124 Parma, Italy
- UdR Parma, INSTM, I-43124 Parma, Italy
| | - E Garlatti
- Dipartimento di Scienze Matematiche, Fisiche e Informatiche, Università di Parma, I-43124 Parma, Italy
- INFN-Sezione di Milano-Bicocca, Gruppo Collegato di Parma, 43124 Parma, Italy
- UdR Parma, INSTM, I-43124 Parma, Italy
| | - F Luis
- Instituto de Nanociencia y Materiales de Aragon (INMA), CSIC, Universidad de Zaragoza, Zaragoza, Spain
- Departamento de Fısica de la Materia Condensada, Universidad de Zaragoza, Zaragoza, Spain
| | - S Carretta
- Dipartimento di Scienze Matematiche, Fisiche e Informatiche, Università di Parma, I-43124 Parma, Italy
- INFN-Sezione di Milano-Bicocca, Gruppo Collegato di Parma, 43124 Parma, Italy
- UdR Parma, INSTM, I-43124 Parma, Italy
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4
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Garlatti E, Albino A, Chicco S, Nguyen VHA, Santanni F, Paolasini L, Mazzoli C, Caciuffo R, Totti F, Santini P, Sessoli R, Lunghi A, Carretta S. The critical role of ultra-low-energy vibrations in the relaxation dynamics of molecular qubits. Nat Commun 2023; 14:1653. [PMID: 36964152 PMCID: PMC10039010 DOI: 10.1038/s41467-023-36852-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 02/15/2023] [Indexed: 03/26/2023] Open
Abstract
Improving the performance of molecular qubits is a fundamental milestone towards unleashing the power of molecular magnetism in the second quantum revolution. Taming spin relaxation and decoherence due to vibrations is crucial to reach this milestone, but this is hindered by our lack of understanding on the nature of vibrations and their coupling to spins. Here we propose a synergistic approach to study a prototypical molecular qubit. It combines inelastic X-ray scattering to measure phonon dispersions along the main symmetry directions of the crystal and spin dynamics simulations based on DFT. We show that the canonical Debye picture of lattice dynamics breaks down and that intra-molecular vibrations with very-low energies of 1-2 meV are largely responsible for spin relaxation up to ambient temperature. We identify the origin of these modes, thus providing a rationale for improving spin coherence. The power and flexibility of our approach open new avenues for the investigation of magnetic molecules with the potential of removing roadblocks toward their use in quantum devices.
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Affiliation(s)
- E Garlatti
- Dipartimento di Scienze Matematiche, Fisiche e Informatiche, Università di Parma and UdR Parma, INSTM, I-43124, Parma, Italy
- INFN, Sezione di Milano-Bicocca, gruppo collegato di Parma, I-43124, Parma, Italy
| | - A Albino
- Dipartimento di Chimica 'Ugo Schiff', Università Degli Studi di Firenze and UdR Firenze, INSTM, I-50019, Sesto Fiorentino, Italy
| | - S Chicco
- Dipartimento di Scienze Matematiche, Fisiche e Informatiche, Università di Parma and UdR Parma, INSTM, I-43124, Parma, Italy
| | - V H A Nguyen
- School of Physics, AMBER and CRANN Institute, Trinity College, Dublin 2, Ireland
| | - F Santanni
- Dipartimento di Chimica 'Ugo Schiff', Università Degli Studi di Firenze and UdR Firenze, INSTM, I-50019, Sesto Fiorentino, Italy
| | - L Paolasini
- ESRF - The European Synchrotron Radiation Facility, F-38043, Grenoble, Cedex 09, France
| | - C Mazzoli
- National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - R Caciuffo
- INFN, Sezione di Genova, I-16146, Genova, Italy
| | - F Totti
- Dipartimento di Chimica 'Ugo Schiff', Università Degli Studi di Firenze and UdR Firenze, INSTM, I-50019, Sesto Fiorentino, Italy
| | - P Santini
- Dipartimento di Scienze Matematiche, Fisiche e Informatiche, Università di Parma and UdR Parma, INSTM, I-43124, Parma, Italy
- INFN, Sezione di Milano-Bicocca, gruppo collegato di Parma, I-43124, Parma, Italy
| | - R Sessoli
- Dipartimento di Chimica 'Ugo Schiff', Università Degli Studi di Firenze and UdR Firenze, INSTM, I-50019, Sesto Fiorentino, Italy.
| | - A Lunghi
- School of Physics, AMBER and CRANN Institute, Trinity College, Dublin 2, Ireland.
| | - S Carretta
- Dipartimento di Scienze Matematiche, Fisiche e Informatiche, Università di Parma and UdR Parma, INSTM, I-43124, Parma, Italy.
- INFN, Sezione di Milano-Bicocca, gruppo collegato di Parma, I-43124, Parma, Italy.
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5
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Mironov VS, Bazhenova TA, Manakin YV, Yagubskii EB. Pentagonal-bipyramidal 4d and 5d complexes with unquenched orbital angular momentum as a unique platform for advanced single-molecule magnets: current state and perspectives. Dalton Trans 2023; 52:509-539. [PMID: 36537237 DOI: 10.1039/d2dt02954e] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
This article overviews the current state and prospects of the concept of advanced single-molecule magnets (SMMs) based on low-spin (S = 1/2) pentagonal-bipyramidal (PBP) 4d3 and 5d3 complexes with unquenched orbital angular momentum. This approach is based on the unique property of PBP 4d3 and 5d3 complexes to cause highly anisotropic spin coupling of perfect uniaxial symmetry, -JzSziSzj - Jxy(SxiSxj + SyiSyj), regardless of the local geometric symmetry. The M(4d/5d)-M(3d) exchange-coupled pairs in the apical positions of the PBP complexes produce Ising-type exchange interactions (|Jz| > |Jxy|), which serve as a powerful source of uniaxial magnetic anisotropy of a SMM cluster. In polynuclear heterometallic 4d/5d-3d complexes embodying PBP 4d/5d units and high-spin 3d ions, anisotropic Ising-type exchange interactions produce a double-well potential with high energy barriers Ueff, which is controlled by the anisotropic exchange parameters Jz, Jxy. Theoretical analysis shows that the barrier is proportional to the difference |Jz - Jxy| and to the number n of the apical 4d/5d-3d pairs in a SMM cluster, Ueff ∝ |Jz - Jxy|n, which provides an opportunity to scale up the barrier Ueff and blocking temperature TB up to the record values. A novel family of 4d/5d complexes with forced PBP coordination provided by structurally rigid planar pentadentate Schiff-base ligands in the equatorial plane is discussed as a better alternative to the cyanometallates. The possibility of a significant increase in the anisotropic exchange parameters Jz, Jxy in PBP complexes with monoatomic apical μ-bridging ligands is examined. The basic principles of molecular engineering the highest barrier through anisotropic exchange interactions of PBP 4d/5d complexes are formulated. The theoretical and experimental results taken together indicate that the concept of high-performance SMMs based on 4d/5d PBP complexes with unquenched orbital angular momentum is an attractive alternative to the currently dominant lanthanide-based SMM strategy.
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Affiliation(s)
- V S Mironov
- Institute of Problems of Chemical Physics RAS, Federal Research Center of Problems of Chemical Physics and Medical Chemistry RAS, Chernogolovka 142432, Russia. .,Shubnikov Institute of Crystallography of Federal Scientific Research Centre "Crystallography and Photonics" RAS, Moscow, Russia
| | - T A Bazhenova
- Institute of Problems of Chemical Physics RAS, Federal Research Center of Problems of Chemical Physics and Medical Chemistry RAS, Chernogolovka 142432, Russia.
| | - Yu V Manakin
- Institute of Problems of Chemical Physics RAS, Federal Research Center of Problems of Chemical Physics and Medical Chemistry RAS, Chernogolovka 142432, Russia.
| | - E B Yagubskii
- Institute of Problems of Chemical Physics RAS, Federal Research Center of Problems of Chemical Physics and Medical Chemistry RAS, Chernogolovka 142432, Russia.
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6
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Rubín J, Arauzo A, Bartolomé E, Sedona F, Rancan M, Armelao L, Luzón J, Guidi T, Garlatti E, Wilhelm F, Rogalev A, Amann A, Spagna S, Bartolomé J, Bartolomé F. Origin of the Unusual Ground-State Spin S = 9 in a Cr 10 Single-Molecule Magnet. J Am Chem Soc 2022; 144:12520-12535. [PMID: 35759747 PMCID: PMC9979690 DOI: 10.1021/jacs.2c05453] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The molecular wheel [Cr10(OMe)20(O2CCMe3)10], abbreviated {Cr10}, with an unusual intermediate total spin S = 9 and non-negligible cluster anisotropy, D/kB = -0.045(2) K, is a rare case among wheels based on an even number of 3d-metals, which usually present an antiferromagnetic (AF) ground state (S = 0). Herein, we unveil the origin of such a behavior. Angular magnetometry measurements performed on a single crystal confirmed the axial anisotropic behavior of {Cr10}. For powder samples, the temperature dependence of the susceptibility plotted as χT(T) showed an overall ferromagnetic (FM) behavior down to 1.8 K, whereas the magnetization curve M(H) did not saturate at the expected 30 μB/fu for 10 FM coupled 3/2 spin Cr3+ ions, but to a much lower value, corresponding to S = 9. In addition, the X-ray magnetic circular dichroism (XMCD) measured at high magnetic field (170 kOe) and 7.5 K showed the polarization of the cluster moment up to 23 μB/fu. The magnetic results can be rationalized within a model, including the cluster anisotropy, in which the {Cr10} wheel is formed by two semiwheels, each with four Cr3+ spins FM coupled (JFM/kB = 2.0 K), separated by two Cr3+ ions AF coupled asymmetrically (J23/kB = J78/kB = -2.0 K; J34/kB = J89/kB = -0.25 K). Inelastic neutron scattering and heat capacity allowed us to confirm this model leading to the S = 9 ground state and first excited S = 8. Single-molecule magnet behavior with an activation energy of U/kB = 4.0(5) K in the absence of applied field was observed through ac susceptibility measurements down to 0.1 K. The intriguing magnetic behavior of {Cr10} arises from the detailed asymmetry in the molecule interactions produced by small-angle distortions in the angles of the Cr-O-Cr alkoxy bridges coupling the Cr3+ ions, as demonstrated by ab initio and density functional theory calculations, while the cluster anisotropy can be correlated to the single-ion anisotropies calculated for each Cr3+ ion in the wheel.
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Affiliation(s)
- Javier Rubín
- Instituto
de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, 50009 Zaragoza, Spain,Departamento
de Ciencia y Tecnología de Materiales y Fluidos, Universidad de Zaragoza, 50018 Zaragoza, Spain,
| | - Ana Arauzo
- Instituto
de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, 50009 Zaragoza, Spain,Servicio
de Medidas Físicas, Universidad de
Zaragoza, Pedro Cerbuna
12, 50009 Zaragoza, Spain,Departamento
de Física de la Materia Condensada, Universidad de Zaragoza, 50009 Zaragoza, Spain
| | - Elena Bartolomé
- Escola
Universitària Salesiana de Sarrià (EUSS), Passeig Sant Joan Bosco 74, 08017 Barcelona, Spain,
| | - Francesco Sedona
- Dipartimento
di Scienze Chimiche, Università di
Padova, Via Marzolo 1, 35131 Padova, Italy
| | - Marzio Rancan
- Institute
of Condensed Matter Chemistry and Technologies for Energy (ICMATE),
National Research Council (CNR), c/o Department of Chemistry, University of Padova, via F. Marzolo 1, 35131 Padova, Italy
| | - Lidia Armelao
- Dipartimento
di Scienze Chimiche, Università di
Padova, Via Marzolo 1, 35131 Padova, Italy,Department
of Chemical Sciences and Materials Technologies (DSCTM), National Research Council (CNR), Piazzale A. Moro 7, 00185 Roma, Italy
| | - Javier Luzón
- Academia
General Militar, Centro Universitario de
la Defensa, 50090 Zaragoza, Spain
| | - Tatiana Guidi
- Physics
Division, School of Science and Technology, University of Camerino, Via Madonna delle Carceri 9, 62032 Camerino, MC, Italy,ISIS
Facility, Rutherford Appleton Laboratory, Chilton, Didcot OX11 0QX, Oxfordshire, U.K.
| | - Elena Garlatti
- Dipartimento
di Science Matematiche, Fisiche e Informatiche, Università di Parma, Parco Area delle Scienze 7/A, 43124 Parma, Italy
| | - Fabrice Wilhelm
- ESRF − The European Synchrotron Radiation Facility, 71 Avenue des Martyrs CS40220, F-38043 Grenoble Cedex 09, France
| | - Andrei Rogalev
- ESRF − The European Synchrotron Radiation Facility, 71 Avenue des Martyrs CS40220, F-38043 Grenoble Cedex 09, France
| | - Andreas Amann
- Quantum Design Inc., San Diego, California 92121, United States
| | - Stefano Spagna
- Quantum Design Inc., San Diego, California 92121, United States
| | - Juan Bartolomé
- Instituto
de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, 50009 Zaragoza, Spain,Departamento
de Física de la Materia Condensada, Universidad de Zaragoza, 50009 Zaragoza, Spain
| | - Fernando Bartolomé
- Instituto
de Nanociencia y Materiales de Aragón (INMA), CSIC-Universidad de Zaragoza, 50009 Zaragoza, Spain,Departamento
de Física de la Materia Condensada, Universidad de Zaragoza, 50009 Zaragoza, Spain,
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7
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Lewis AJ, Garlatti E, Cugini F, Solzi M, Zeller M, Carretta S, Zaleski CM. Slow Magnetic Relaxation of a 12-Metallacrown-4 Complex with a Manganese(III)–Copper(II) Heterometallic Ring Motif. Inorg Chem 2020; 59:11894-11900. [DOI: 10.1021/acs.inorgchem.0c01410] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Alex J. Lewis
- Department of Chemistry and Biochemistry, Shippensburg University, Shippensburg, Pennsylvania 17257, United States
| | - Elena Garlatti
- Dipartimento di Scienze Matematiche, Fisiche e Informatiche, Università di Parma, 1-43124 Parma, Italy
- Udr Parma, INSTM, 1-43124 Parma, Italy
| | - Francesco Cugini
- Dipartimento di Scienze Matematiche, Fisiche e Informatiche, Università di Parma, 1-43124 Parma, Italy
| | - Massimo Solzi
- Dipartimento di Scienze Matematiche, Fisiche e Informatiche, Università di Parma, 1-43124 Parma, Italy
| | - Matthias Zeller
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States
| | - Stefano Carretta
- Dipartimento di Scienze Matematiche, Fisiche e Informatiche, Università di Parma, 1-43124 Parma, Italy
- Udr Parma, INSTM, 1-43124 Parma, Italy
| | - Curtis M. Zaleski
- Department of Chemistry and Biochemistry, Shippensburg University, Shippensburg, Pennsylvania 17257, United States
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8
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Garlatti E, Allodi G, Bordignon S, Bordonali L, Timco GA, Winpenny REP, Lascialfari A, De Renzi R, Carretta S. Breaking the ring: 53Cr-NMR on the Cr 8Cd molecular nanomagnet. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:244003. [PMID: 32079012 DOI: 10.1088/1361-648x/ab7872] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
An accurate experimental characterization of finite antiferromagnetic (AF) spin chains is crucial for controlling and manipulating their magnetic properties and quantum states for potential applications in spintronics or quantum computation. In particular, finite AF chains are expected to show a different magnetic behaviour depending on their length and topology. Molecular AF rings are able to combine the quantum-magnetic behaviour of AF chains with a very remarkable tunability of their topological and geometrical properties. In this work we measure the 53Cr-NMR spectra of the Cr8Cd ring to study the local spin densities on the Cr sites. Cr8Cd can in fact be considered a model system of a finite AF open chain with an even number of spins. The NMR resonant frequencies are in good agreement with the theoretical local spin densities, by assuming a core polarization field A C = -12.7 T μ B -1. Moreover, these NMR results confirm the theoretically predicted non-collinear spin arrangement along the Cr8Cd ring, which is typical of an even-open AF spin chain.
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Affiliation(s)
- E Garlatti
- Dipartimento di Science Matematiche, Fisiche e Informatiche, Università di Parma, Parco Area delle Scienze 7/A, 43124 Parma, Italy
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9
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Garlatti E, Tesi L, Lunghi A, Atzori M, Voneshen DJ, Santini P, Sanvito S, Guidi T, Sessoli R, Carretta S. Unveiling phonons in a molecular qubit with four-dimensional inelastic neutron scattering and density functional theory. Nat Commun 2020; 11:1751. [PMID: 32273510 PMCID: PMC7145838 DOI: 10.1038/s41467-020-15475-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Accepted: 03/05/2020] [Indexed: 11/09/2022] Open
Abstract
Phonons are the main source of relaxation in molecular nanomagnets, and different mechanisms have been proposed in order to explain the wealth of experimental findings. However, very limited experimental investigations on phonons in these systems have been performed so far, yielding no information about their dispersions. Here we exploit state-of-the-art single-crystal inelastic neutron scattering to directly measure for the first time phonon dispersions in a prototypical molecular qubit. Both acoustic and optical branches are detected in crystals of [VO(acac)[Formula: see text]] along different directions in the reciprocal space. Using energies and polarisation vectors calculated with state-of-the-art Density Functional Theory, we reproduce important qualitative features of [VO(acac)[Formula: see text]] phonon modes, such as the presence of low-lying optical branches. Moreover, we evidence phonon anti-crossings involving acoustic and optical branches, yielding significant transfers of the spin-phonon coupling strength between the different modes.
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Affiliation(s)
- E Garlatti
- ISIS Facility, Rutherford Appleton Laboratory, Didcot, OX11 0QX, UK.,Dipartimento di Science Matematiche, Fisiche e Informatiche, Università di Parma and UdR Parma, INSTM, Parco Area delle Scienze 7/A, 43124, Parma, Italy
| | - L Tesi
- Dipartimento di Chimica U. Schiff, Università degli Studi di Firenze and UdR Firenze, INSTM, Via della Lastruccia 3, I50019, Sesto Fiorentino, Firenze, Italy.,Institute of Physical Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany
| | - A Lunghi
- School of Physics, CRANN and AMBER Trinity College, Dublin 2, Ireland
| | - M Atzori
- Dipartimento di Chimica U. Schiff, Università degli Studi di Firenze and UdR Firenze, INSTM, Via della Lastruccia 3, I50019, Sesto Fiorentino, Firenze, Italy.,Laboratoire National des Champs Magnétiques Intenses (LNCMI) - CNRS, 25 rue des Martyrs, 38042, Grenoble, France
| | - D J Voneshen
- ISIS Facility, Rutherford Appleton Laboratory, Didcot, OX11 0QX, UK
| | - P Santini
- Dipartimento di Science Matematiche, Fisiche e Informatiche, Università di Parma and UdR Parma, INSTM, Parco Area delle Scienze 7/A, 43124, Parma, Italy
| | - S Sanvito
- School of Physics, CRANN and AMBER Trinity College, Dublin 2, Ireland
| | - T Guidi
- ISIS Facility, Rutherford Appleton Laboratory, Didcot, OX11 0QX, UK.
| | - R Sessoli
- Dipartimento di Chimica U. Schiff, Università degli Studi di Firenze and UdR Firenze, INSTM, Via della Lastruccia 3, I50019, Sesto Fiorentino, Firenze, Italy.
| | - S Carretta
- Dipartimento di Science Matematiche, Fisiche e Informatiche, Università di Parma and UdR Parma, INSTM, Parco Area delle Scienze 7/A, 43124, Parma, Italy.
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10
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Dunstan MA, Mole RA, Boskovic C. Inelastic Neutron Scattering of Lanthanoid Complexes and Single‐Molecule Magnets. Eur J Inorg Chem 2019. [DOI: 10.1002/ejic.201801306] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Maja A. Dunstan
- School of Chemistry University of Melbourne Parkville, Victoria, 3010 Australia
| | - Richard A. Mole
- Australian Centre for Neutron Scattering Australian Nuclear Science and Technology Organisation Locked Bag 2001, Kirrawee DC, NSW, 2232 Australia
| | - Colette Boskovic
- School of Chemistry University of Melbourne Parkville, Victoria, 3010 Australia
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11
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Garlatti E, Chiesa A, Guidi T, Amoretti G, Santini P, Carretta S. Unravelling the Spin Dynamics of Molecular Nanomagnets with Four‐Dimensional Inelastic Neutron Scattering. Eur J Inorg Chem 2019. [DOI: 10.1002/ejic.201801050] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Elena Garlatti
- Dipartimento di Science Matematiche, Fisiche e Informatiche Università di Parma Parco Area delle Scienze n.7/A 43124 Parma Italy
- ISIS Neutron and Muon Source Rutherford Appleton Laboratory OX11 0QX Didcot UK
| | - Alessandro Chiesa
- Dipartimento di Science Matematiche, Fisiche e Informatiche Università di Parma Parco Area delle Scienze n.7/A 43124 Parma Italy
| | - Tatiana Guidi
- ISIS Neutron and Muon Source Rutherford Appleton Laboratory OX11 0QX Didcot UK
| | - Giuseppe Amoretti
- Dipartimento di Science Matematiche, Fisiche e Informatiche Università di Parma Parco Area delle Scienze n.7/A 43124 Parma Italy
| | - Paolo Santini
- Dipartimento di Science Matematiche, Fisiche e Informatiche Università di Parma Parco Area delle Scienze n.7/A 43124 Parma Italy
| | - Stefano Carretta
- Dipartimento di Science Matematiche, Fisiche e Informatiche Università di Parma Parco Area delle Scienze n.7/A 43124 Parma Italy
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12
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Goleva K, Naumova D, Pavlishchuk A, Addison AW, Zeller M. Crystal structure of bis-(pivaloyl-hydroxamato-κ 2O, O')copper(II). Acta Crystallogr E Crystallogr Commun 2018; 74:1384-1387. [PMID: 30225137 PMCID: PMC6127706 DOI: 10.1107/s2056989018012227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 08/28/2018] [Indexed: 11/10/2022]
Abstract
Reaction of copper(II) nitrate with pivaloyl-hydroxamic acid yielded the title compound, [Cu(pivHA)2] (where pivHA- is pivaloyl hydroxamate, C5H10NO2). The centrosymmetric mononuclear complex consists of a CuII ion, which is located on a center of inversion, with two coordinated pivaloyl hydroxamate monoanions. The CuII ion has a square-planar coordination environment consisting of four O atoms - two carbonyl O atoms and two hydroxamate O atoms from two hydroxamate pivHA- ligands. The pivHA- anions are coordinated to copper(II) in a trans-mode, forming two five-membered O,O'-chelate rings.
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Affiliation(s)
- Kateryna Goleva
- Department of Chemistry, Taras Shevchenko National University of Kyiv, Volodymyrska str. 62, Kiev, 01601, Ukraine
| | - Dina Naumova
- Department of Chemistry, Taras Shevchenko National University of Kyiv, Volodymyrska str. 62, Kiev, 01601, Ukraine
| | - Anna Pavlishchuk
- Department of Chemistry, Taras Shevchenko National University of Kyiv, Volodymyrska str. 62, Kiev, 01601, Ukraine
| | - Anthony W. Addison
- Department of Chemistry, Drexel University, Philadelphia, PA 19104-2816, USA
| | - Matthias Zeller
- Department of Chemistry, Purdue University, 560 Oval Dr., West Lafayette, IN 47907-2084, USA
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13
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Ansbro S, Moreno-Pineda E, Yu W, Ollivier J, Mutka H, Ruben M, Chiesa A. Magnetic properties of transition metal dimers probed by inelastic neutron scattering. Dalton Trans 2018; 47:11953-11959. [PMID: 30074034 DOI: 10.1039/c8dt02570c] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The physical characterisation and understanding of molecular magnetic materials is one of the most important steps towards the integration of such systems in hybrid spintronic devices. Amongst the many characterisation techniques employed in such a task, Inelastic Neutron Scattering (INS) stands as one of the most powerful and sensitive tools to investigate their spin dynamics. Herein, the magnetic properties and spin dynamics of two dinuclear complexes, namely [(M(hfacac)2)2(bpym)] (where M = Ni2+, Co2+, abbreviated in the following as Ni2, Co2) are reported. These are model systems that could constitute fundamental units of future spintronic devices. By exploiting the highly sensitive IN5 Cold INS spectrometer, we are able to gain a deep insight into the spin dynamics of Ni2 and to fully obtain the microscopic spin Hamiltonian parameters; while for Co2, a multitude of INS transitions are observed demonstrating the complexity of the magnetic properties of octahedral cobalt-based systems.
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Affiliation(s)
- Simon Ansbro
- School of Chemistry, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
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14
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Collet A, Craig GA, Heras Ojea MJ, Bhaskaran L, Wilson C, Hill S, Murrie M. Slow magnetic relaxation in a {Co IICo} complex containing a high magnetic anisotropy trigonal bipyramidal Co II centre. Dalton Trans 2018; 47:9237-9240. [PMID: 29953164 DOI: 10.1039/c8dt01997e] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
We report a trinuclear mixed-valence {CoIICoIII2} complex, where the CoII centre adopts a trigonal bipyramidal geometry, leading to a large, easy-plane magnetic anisotropy and field-induced slow magnetic relaxation with a Raman-like relaxation process.
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Affiliation(s)
- Alexandra Collet
- WestCHEM, School of Chemistry, University of Glasgow, University Avenue, Glasgow, G12 8QQ, UK.
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