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Title: Electric transport coefficients in highly epitaxial LaBaCo{sub 2}O{sub 5 + δ} films with “p-to-n” transition induced by oxygen deficiency

Abstract

Electric transport coefficients such as carrier type, density, and mobility are the important physical parameters in designing functional devices. In this work, we report the study on the electric transport coefficients of the highly epitaxial LaBaCo{sub 2}O{sub 5 + δ} (LBCO) films, which were discussed as a function of electric conductivity for the first time and compared with the results calculated by the theory for mixed conduction. The mobility in the LBCO films was determined to be ∼0.85 and ∼40 cm{sup 2}/V s for holes and electrons, respectively, and the density of p-type carriers strongly depends on the oxygen deficiency. Solid evidence is presented to demonstrate that the oxygen deficiency cannot make LBCO materials changed from p- to n-type. The n-type conduction observed in experiment is a counterfeit phenomenon caused by the deficiency in Hall measurement, rather than a realistic transition induced by oxygen deficiency. In addition, the temperature-dependent conductivity was discussed using the differential coefficients, which might be useful in the study of the samples with magnetic transition.

Authors:
; ; ; ;  [1];  [2]
  1. Key Laboratory of Materials Modification by Laser, Ion and Electron Beams, and School of Physics and Opto-electronic Technology, Dalian University of Technology, Dalian 116024 (China)
  2. College of Physics, Qingdao University, Qingdao 266071 (China)
Publication Date:
OSTI Identifier:
22597706
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 120; Journal Issue: 6; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; CARRIERS; COMPARATIVE EVALUATIONS; DENSITY; ELECTRIC CONDUCTIVITY; ELECTRONS; EPITAXY; FILMS; MOBILITY; OXYGEN; TEMPERATURE DEPENDENCE; TRANSPORT THEORY

Citation Formats

Shaibo, J., Zhang, Q. Y., E-mail: qyzhang@dlut.edu.cn, Hu, H. C., Li, X. N., Pan, L. J., and Wang, Y. Q. Electric transport coefficients in highly epitaxial LaBaCo{sub 2}O{sub 5 + δ} films with “p-to-n” transition induced by oxygen deficiency. United States: N. p., 2016. Web. doi:10.1063/1.4960688.
Shaibo, J., Zhang, Q. Y., E-mail: qyzhang@dlut.edu.cn, Hu, H. C., Li, X. N., Pan, L. J., & Wang, Y. Q. Electric transport coefficients in highly epitaxial LaBaCo{sub 2}O{sub 5 + δ} films with “p-to-n” transition induced by oxygen deficiency. United States. doi:10.1063/1.4960688.
Shaibo, J., Zhang, Q. Y., E-mail: qyzhang@dlut.edu.cn, Hu, H. C., Li, X. N., Pan, L. J., and Wang, Y. Q. 2016. "Electric transport coefficients in highly epitaxial LaBaCo{sub 2}O{sub 5 + δ} films with “p-to-n” transition induced by oxygen deficiency". United States. doi:10.1063/1.4960688.
@article{osti_22597706,
title = {Electric transport coefficients in highly epitaxial LaBaCo{sub 2}O{sub 5 + δ} films with “p-to-n” transition induced by oxygen deficiency},
author = {Shaibo, J. and Zhang, Q. Y., E-mail: qyzhang@dlut.edu.cn and Hu, H. C. and Li, X. N. and Pan, L. J. and Wang, Y. Q.},
abstractNote = {Electric transport coefficients such as carrier type, density, and mobility are the important physical parameters in designing functional devices. In this work, we report the study on the electric transport coefficients of the highly epitaxial LaBaCo{sub 2}O{sub 5 + δ} (LBCO) films, which were discussed as a function of electric conductivity for the first time and compared with the results calculated by the theory for mixed conduction. The mobility in the LBCO films was determined to be ∼0.85 and ∼40 cm{sup 2}/V s for holes and electrons, respectively, and the density of p-type carriers strongly depends on the oxygen deficiency. Solid evidence is presented to demonstrate that the oxygen deficiency cannot make LBCO materials changed from p- to n-type. The n-type conduction observed in experiment is a counterfeit phenomenon caused by the deficiency in Hall measurement, rather than a realistic transition induced by oxygen deficiency. In addition, the temperature-dependent conductivity was discussed using the differential coefficients, which might be useful in the study of the samples with magnetic transition.},
doi = {10.1063/1.4960688},
journal = {Journal of Applied Physics},
number = 6,
volume = 120,
place = {United States},
year = 2016,
month = 8
}
  • A giant magnetoresistance effect (∼46% at 20 K under 7 T) and anomalous magnetic properties were found in a highly epitaxial double perovskite LaBaCo{sub 2}O{sub 5.5+δ} (LBCO) thin film on (001) MgO. Aberration-corrected Electron Microscopy and related analytical techniques were employed to understand the nature of these unusual physical properties. The as-grown film is epitaxial with the c-axis of the LBCO structure lying in the film plane and with an interface relationship given by (100){sub LBCO} || (001){sub MgO} and [001]{sub LBCO} || [100]{sub MgO} or [010]{sub MgO}. Orderly oxygen vacancies were observed by line profile electron energy loss spectroscopy and bymore » atomic resolution imaging. Especially, oxygen vacancy and nanodomain structures were found to have a crucial effect on the electronic transport and magnetic properties.« less
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  • We analyzed the crystallographic c-axis tilt of (001) Y 2O 3 films grown on biaxially textured Ni-5%W tapes under different oxygen flux conditions. We found that different tilting mechanisms were effective in films with different oxygen stoichiometry. Moreover, the structure of the film/substrate interface, investigated by TEM, and the residual strain of the film, investigated by XRD, were also dependent on the film oxygen content. While the oxygen stoichiometric Y 2O 3 sample exhibited a coherent film/substrate interface and the sharpest out-of-plane texture, the films grown under reduced oxygen pressure exhibited a smaller overall c-axis tilt due to formation ofmore » interface dislocations and regions in which the film oxygen vacancies ordered to form a lattice superstructure.« less
  • Fluctuation analysis in the limit of high magnetic fields was performed on three epitaxial thin films of YBa[sub 2]Cu[sub 3]O[sub 7[minus][delta]] for various oxygen deficiencies [delta][lt]0.3. On the 90-K plateau, the three-dimensional (3D) limit yielded an [ital H][sub [ital c]2]([ital T]) slope of [minus]1.7 T/K for [ital H][parallel][ital c], consistent with previous observations of transport and magnetic properties. Moreover, the 3D scaling showed better convergence than the 2D scaling, which gave relatively low values of [ital H][sub [ital c]2]. In contrast, the transitions were not adequately described by either scaling for [ital T][sub [ital c]] off the 90-K plateau; itmore » is speculated that this is due to an extrinsic broadening of the transitions, possibly due to the lack of a complete percolation path of the ortho-[ital I] phase ([delta]=0).« less