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Title: Stoichiometry determined exchange interactions in amorphous ternary transition metal oxides: Theory and experiment

Abstract

Amorphous transition metal oxides exhibit exotic transport and magnetic properties, while the absence of periodic structure has long been a major obstacle for the understanding of their electronic structure and exchange interaction. In this paper, we have formulated a theoretical approach, which combines the melt-quench approach and the spin dynamic Monte-Carlo simulations, and based on it, we explored amorphous Co{sub 0.5}Zn{sub 0.5}O{sub 1−y} ternary transition metal oxides. Our theoretical results reveal that the microstructure, the magnetic properties, and the exchange interactions of Co{sub 0.5}Zn{sub 0.5}O{sub 1−y} are strongly determined by the oxygen stoichiometry. In the oxygen-deficient sample (y > 0), we have observed the long-range ferromagnetic spin ordering which is associated with the non-stoichiometric cobalt-rich region rather than metallic clusters. On the other hand, the microstructure of stoichiometric sample takes the form of continuous random networks, and no long-range ferromagnetism has been observed in it. Magnetization characterization of experimental synthesized Co{sub 0.61}Zn{sub 0.39}O{sub 1−y} films verifies the relation between the spin ordering and the oxygen stoichiometry. Furthermore, the temperature dependence of electrical transport shows a typical feature of semiconductors, in agreement with our theoretical results.

Authors:
; ; ; ; ;  [1]
  1. School of Physics, National Key Laboratory of Crystal Materials, Shandong University, Jinan, Shandong 250100 (China)
Publication Date:
OSTI Identifier:
22308535
Resource Type:
Journal Article
Journal Name:
Journal of Applied Physics
Additional Journal Information:
Journal Volume: 116; Journal Issue: 4; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0021-8979
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; AMORPHOUS STATE; COBALT COMPOUNDS; COMPUTERIZED SIMULATION; ELECTRONIC STRUCTURE; EXCHANGE INTERACTIONS; FERROMAGNETISM; FILMS; MAGNETIC PROPERTIES; MAGNETIZATION; MICROSTRUCTURE; MONTE CARLO METHOD; OXIDES; OXYGEN COMPOUNDS; PERIODICITY; SEMICONDUCTOR MATERIALS; SPIN; STOICHIOMETRY; TEMPERATURE DEPENDENCE; TRANSITION ELEMENT COMPOUNDS; ZINC COMPOUNDS

Citation Formats

Hu, Shu-jun, Yan, Shi-shen, Zhang, Yun-peng, Zhao, Ming-wen, Kang, Shi-shou, and Mei, Liang-mo. Stoichiometry determined exchange interactions in amorphous ternary transition metal oxides: Theory and experiment. United States: N. p., 2014. Web. doi:10.1063/1.4891474.
Hu, Shu-jun, Yan, Shi-shen, Zhang, Yun-peng, Zhao, Ming-wen, Kang, Shi-shou, & Mei, Liang-mo. Stoichiometry determined exchange interactions in amorphous ternary transition metal oxides: Theory and experiment. United States. https://doi.org/10.1063/1.4891474
Hu, Shu-jun, Yan, Shi-shen, Zhang, Yun-peng, Zhao, Ming-wen, Kang, Shi-shou, and Mei, Liang-mo. 2014. "Stoichiometry determined exchange interactions in amorphous ternary transition metal oxides: Theory and experiment". United States. https://doi.org/10.1063/1.4891474.
@article{osti_22308535,
title = {Stoichiometry determined exchange interactions in amorphous ternary transition metal oxides: Theory and experiment},
author = {Hu, Shu-jun and Yan, Shi-shen and Zhang, Yun-peng and Zhao, Ming-wen and Kang, Shi-shou and Mei, Liang-mo},
abstractNote = {Amorphous transition metal oxides exhibit exotic transport and magnetic properties, while the absence of periodic structure has long been a major obstacle for the understanding of their electronic structure and exchange interaction. In this paper, we have formulated a theoretical approach, which combines the melt-quench approach and the spin dynamic Monte-Carlo simulations, and based on it, we explored amorphous Co{sub 0.5}Zn{sub 0.5}O{sub 1−y} ternary transition metal oxides. Our theoretical results reveal that the microstructure, the magnetic properties, and the exchange interactions of Co{sub 0.5}Zn{sub 0.5}O{sub 1−y} are strongly determined by the oxygen stoichiometry. In the oxygen-deficient sample (y > 0), we have observed the long-range ferromagnetic spin ordering which is associated with the non-stoichiometric cobalt-rich region rather than metallic clusters. On the other hand, the microstructure of stoichiometric sample takes the form of continuous random networks, and no long-range ferromagnetism has been observed in it. Magnetization characterization of experimental synthesized Co{sub 0.61}Zn{sub 0.39}O{sub 1−y} films verifies the relation between the spin ordering and the oxygen stoichiometry. Furthermore, the temperature dependence of electrical transport shows a typical feature of semiconductors, in agreement with our theoretical results.},
doi = {10.1063/1.4891474},
url = {https://www.osti.gov/biblio/22308535}, journal = {Journal of Applied Physics},
issn = {0021-8979},
number = 4,
volume = 116,
place = {United States},
year = {Mon Jul 28 00:00:00 EDT 2014},
month = {Mon Jul 28 00:00:00 EDT 2014}
}