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Machado P, Guzmán R, Morera RJ, Alcalà J, Palau A, Zhou W, Coll M. Chemical Synthesis of La 0.75Sr 0.25CrO 3 Thin Films for p-Type Transparent Conducting Electrodes. CHEMISTRY OF MATERIALS : A PUBLICATION OF THE AMERICAN CHEMICAL SOCIETY 2023; 35:3513-3521. [PMID: 37181670 PMCID: PMC10173867 DOI: 10.1021/acs.chemmater.2c03831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 03/24/2023] [Indexed: 05/16/2023]
Abstract
The imperative need for highly performant and stable p-type transparent electrodes based on abundant metals is stimulating the research on perovskite oxide thin films. Moreover, exploring the preparation of these materials with the use of cost-efficient and scalable solution-based techniques is a promising approach to extract their full potential. Herein, we present the design of a chemical route, based on metal nitrate precursors, for the preparation of pure phase La0.75Sr0.25CrO3 (LSCO) thin films to be used as a p-type transparent conductive electrode. Different solution chemistries have been evaluated to ultimately obtain dense, epitaxial, and almost relaxed LSCO films. Optical characterization of the optimized LSCO films reveals promising high transparency with ∼67% transmittance while room temperature resistivity values are 1.4 Ω·cm. It is suggested that the presence of structural defects, i.e., antiphase boundaries and misfit dislocations, affects the electrical behavior of LSCO films. Monochromated electron energy loss spectroscopy allowed changes in the electronic structure in LSCO films to be determined, revealing the creation of Cr4+ and unoccupied states at the O 2p upon Sr-doping. This work offers a new venue to prepare and further investigate cost-effective functional perovskite oxides with potential to be used as p-type transparent conducting electrodes and be easily integrated in many oxide heterostructures.
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Affiliation(s)
- Pamela Machado
- Institut
de Ciència de Materials de Barcelona ICMAB-CSIC, Campus UAB, Bellaterra 08193, Spain
| | - Roger Guzmán
- School
of Physical Sciences, University of Chinese
Academy of Sciences, Beijing 100049, China
| | - Ramon J. Morera
- Institut
de Ciència de Materials de Barcelona ICMAB-CSIC, Campus UAB, Bellaterra 08193, Spain
| | - Jordi Alcalà
- Institut
de Ciència de Materials de Barcelona ICMAB-CSIC, Campus UAB, Bellaterra 08193, Spain
| | - Anna Palau
- Institut
de Ciència de Materials de Barcelona ICMAB-CSIC, Campus UAB, Bellaterra 08193, Spain
| | - Wu Zhou
- School
of Physical Sciences, University of Chinese
Academy of Sciences, Beijing 100049, China
| | - Mariona Coll
- Institut
de Ciència de Materials de Barcelona ICMAB-CSIC, Campus UAB, Bellaterra 08193, Spain
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2
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Zhou G, Li Z, Dou J, Ji H, Kang P, Shen Y, Wang S, Xu X. The polar and nonpolar interfaces influenced of magnetism in LaMnO 3-based superlattices. RSC Adv 2023; 13:10254-10260. [PMID: 37006349 PMCID: PMC10065140 DOI: 10.1039/d3ra00229b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 03/28/2023] [Indexed: 04/03/2023] Open
Abstract
The interface of perovskite heterostructures has been shown to exhibit various electronic and magnetic phases such as two-dimensional electron gas, magnetism, superconductivity, and electronic phase separation. These rich phases are expected due to the strong interplay between spin, charge, and orbital degree of freedom at the interface. In this work, the polar and nonpolar interfaces are designed in LaMnO3-based (LMO) superlattices to investigate the difference in magnetic and transport properties. For the polar interface in a LMO/SrMnO3 superlattice, a novel robust ferromagnetism, exchange bias effect, vertical magnetization shift, and metallic behaviors coexist due to the polar catastrophe, which results in a double exchange coupling effect in the interface. For the nonpolar interface in a LMO/LaNiO3 superlattice, only the ferromagnetism and exchange bias effect characteristics exist due to the polar continuous interface. This is attributed to the charge transfer between Mn3+ and Ni3+ ions at the interface. Therefore, transition metal oxides exhibit various novel physical properties due to the strong correlation of d electrons and the polar and nonpolar interfaces. Our observations may provide an approach to further tune the properties using the selected polar and nonpolar oxide interfaces. The interface of perovskite heterostructures has been shown to exhibit various electronic and magnetic phases such as two-dimensional electron gas, magnetism, superconductivity, and electronic phase separation![]()
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Affiliation(s)
- Guowei Zhou
- School of Chemistry and Materials Science of Shanxi Normal University, Key Laboratory of Magnetic Molecules and Magnetic Information Materials of Ministry of EducationTaiyuan 030006China
- Research Institute of Materials Science of Shanxi Normal University, Collaborative Innovation Center for Shanxi Advanced Permanent Magnetic Materials and TechonologyTaiyuan 030006China
| | - Zhilan Li
- School of Chemistry and Materials Science of Shanxi Normal University, Key Laboratory of Magnetic Molecules and Magnetic Information Materials of Ministry of EducationTaiyuan 030006China
| | - Jiarui Dou
- School of Chemistry and Materials Science of Shanxi Normal University, Key Laboratory of Magnetic Molecules and Magnetic Information Materials of Ministry of EducationTaiyuan 030006China
| | - Huihui Ji
- School of Chemistry and Materials Science of Shanxi Normal University, Key Laboratory of Magnetic Molecules and Magnetic Information Materials of Ministry of EducationTaiyuan 030006China
- Research Institute of Materials Science of Shanxi Normal University, Collaborative Innovation Center for Shanxi Advanced Permanent Magnetic Materials and TechonologyTaiyuan 030006China
| | - Penghua Kang
- School of Chemistry and Materials Science of Shanxi Normal University, Key Laboratory of Magnetic Molecules and Magnetic Information Materials of Ministry of EducationTaiyuan 030006China
| | - Yufan Shen
- School of Chemistry and Materials Science of Shanxi Normal University, Key Laboratory of Magnetic Molecules and Magnetic Information Materials of Ministry of EducationTaiyuan 030006China
| | - Siqi Wang
- School of Chemistry and Materials Science of Shanxi Normal University, Key Laboratory of Magnetic Molecules and Magnetic Information Materials of Ministry of EducationTaiyuan 030006China
| | - Xiaohong Xu
- School of Chemistry and Materials Science of Shanxi Normal University, Key Laboratory of Magnetic Molecules and Magnetic Information Materials of Ministry of EducationTaiyuan 030006China
- Research Institute of Materials Science of Shanxi Normal University, Collaborative Innovation Center for Shanxi Advanced Permanent Magnetic Materials and TechonologyTaiyuan 030006China
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Yun C, Li W, Gao X, Dou H, Maity T, Sun X, Wu R, Peng Y, Yang J, Wang H, MacManus-Driscoll JL. Creating Ferromagnetic Insulating La 0.9Ba 0.1MnO 3 Thin Films by Tuning Lateral Coherence Length. ACS APPLIED MATERIALS & INTERFACES 2021; 13:8863-8870. [PMID: 33586975 PMCID: PMC8023513 DOI: 10.1021/acsami.1c00607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 01/28/2021] [Indexed: 06/12/2023]
Abstract
In this work, heteroepitaxial vertically aligned nanocomposite (VAN) La0.9Ba0.1MnO3 (LBMO)-CeO2 films are engineered to produce ferromagnetic insulating (FMI) films. From combined X-ray photoelectron spectroscopy, X-ray diffraction, and electron microscopy, the elimination of the insulator-metal (I-M) transition is shown to result from the creation of very small lateral coherence lengths (with the corresponding lateral size ∼ 3 nm (∼7 u.c.)) in the LBMO matrix, achieved by engineering a high density of CeO2 nanocolumns in the matrix. The small lateral coherence length leads to a shift in the valence band maximum and reduction of the double exchange (DE) coupling. There is no "dead layer" effect at the smallest achieved lateral coherence length of ∼3 nm. The FMI behavior obtained by lateral dimensional tuning is independent of substrate interactions, thus intrinsic to the film itself and hence not related to film thickness. The unique properties of VAN films give the possibility for multilayer spintronic devices that can be made without interface degradation effects between the layers.
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Affiliation(s)
- Chao Yun
- Department
of Materials Science and Metallurgy, University
of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS, United Kingdom
- State
Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
| | - Weiwei Li
- Department
of Materials Science and Metallurgy, University
of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS, United Kingdom
| | - Xingyao Gao
- Materials
Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Hongyi Dou
- Materials
Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Tuhin Maity
- Department
of Materials Science and Metallurgy, University
of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS, United Kingdom
- School
of Physics, Indian Institute of Science
Education and Research Thiruvananthapuram, Thiruvananthapuram, Kerala 695551, India
| | - Xing Sun
- Materials
Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Rui Wu
- Department
of Materials Science and Metallurgy, University
of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS, United Kingdom
| | - Yuxuan Peng
- State
Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
| | - Jinbo Yang
- State
Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
| | - Haiyan Wang
- Materials
Engineering, Purdue University, West Lafayette, Indiana 47907, United States
| | - Judith L. MacManus-Driscoll
- Department
of Materials Science and Metallurgy, University
of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS, United Kingdom
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Waschk M, Sarkar A, Barthel J, Voigt J, Schröder S, Zakalek P, Schmitz M, Kirby BJ, Pütter S, Schubert J, Brückel T. Impact of growth kinetics on the interface morphology and magnetization in La 1/3Sr 2/3FeO 3/La 2/3Sr 1/3MnO 3 heterostructures. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:165801. [PMID: 31899900 DOI: 10.1088/1361-648x/ab678c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The ability to create atomically perfect, epitaxial heterostructures of correlated complex perovskite oxides using state-of-art thin film deposition techniques has generated new physical phenomena at engineered interfaces. Here we report on the impact of growth kinetics on the magnetic structure and exchange coupling at the interface in heterostructures combining layers of antiferromagnetic La1/3Sr2/3FeO3 (LSFO) and ferromagnetic La2/3Sr1/3MnO3 (LSMO) on (0 0 1)-oriented SrTiO3 (STO) substrates. Two growth orders are investigated, (a) LSMO/LSFO/STO(0 0 1) and (b) LSFO/LSMO/STO(0 0 1), where the LSFO layer is grown by molecular beam epitaxy and the LSMO layer by high oxygen pressure sputtering. The interface has been investigated using electron microscopy and polarized neutron reflectometry. Interdiffusion over seven monolayers is observed in LSMO/LSFO (a) with an almost 50% reduction in magnetization at the interface and showing no exchange coupling. However, the exchange bias effect ([Formula: see text] mT at 10 K) could be realized when the interface is atomically sharp, as in LSFO/LSMO (b). Our study therefore reveals that, even for well ordered and lattice-matched structures, the kinetics involved in the growth processes drastically influences the interface quality with a strong correlation to the magnetic properties.
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Affiliation(s)
- M Waschk
- Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science (JCNS-2) and Peter Grünberg Institut (PGI-4), JARA-FIT, 52425 Jülich, Germany
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Effects of Oxygen Modification on the Structural and Magnetic Properties of Highly Epitaxial La 0.7Sr 0.3MnO 3 (LSMO) thin films. Sci Rep 2020; 10:3659. [PMID: 32108143 PMCID: PMC7046674 DOI: 10.1038/s41598-020-60343-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Accepted: 02/05/2020] [Indexed: 12/02/2022] Open
Abstract
La0.7Sr0.3MnO3, a strong semi-metallic ferromagnet having robust spin polarization and magnetic transition temperature (TC) well above 300 K, has attracted significant attention as a possible candidate for a wide range of memory, spintronic, and multifunctional devices. Since varying the oxygen partial pressure during growth is likely to change the structural and other physical functionalities of La0.7Sr0.3MnO3 (LSMO) films, here we report detailed investigations on structure, along with magnetic behavior of LSMO films with same thickness (~30 nm) but synthesized at various oxygen partial pressures: 10, 30, 50, 100, 150, 200 and 250 mTorr. The observation of only (00 l) reflections without any secondary peaks in the XRD patterns confirms the high-quality synthesis of the above-mentioned films. Surface morphology of the films reveals that these films are very smooth with low roughness, the thin films synthesized at 150 mTorr having the lowest average roughness. The increasing of magnetic TC and sharpness of the magnetic phase transitions with increasing oxygen growth pressure suggests that by decreasing the oxygen growth pressure leads to oxygen deficiencies in grown films which induce oxygen inhomogeneity. Thin films grown at 150 mTorr exhibits the highest magnetization with TC = 340 K as these thin films possess the lowest roughness and might exhibit lowest oxygen vacancies and defects. Interpretation and significance of these results in the 30 nm LSMO thin films prepared at different oxygen growth pressures are also presented, along with the existence and growth pressure dependence of negative remanent magnetization (NRM) of the above-mentioned thin films.
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