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Title: Low-Temperature Schottky Anomalies and the Magnetic State of the p Electrons of Oxygen in Substituted Gd{sub 0.4}Sr{sub 0.6}CoO{sub 3–δ} Cobaltites

Abstract

The XANES spectra (X-ray absorption near-edge spectra) at the K edge of Co and the L{sub 3} edge of Gd in polycrystalline Gd{sub 0.4}Sr{sub 0.6}CoO{sub 3–δ} rare-earth oxides with an ordered and disordered distribution of Gd{sup 3+} and Sr{sup 2+} cations over the A sites in the crystal lattice are measured. The results of XANES measurements do not reveal a noticeable shift in the absorption edge with increasing Sr concentration as compared to the GdCoO{sub 3} parent composition. The measured temperature dependences of the heat capacity of polycrystalline ordered and disordered samples and a single-crystal ordered Gd{sub 0.4}Sr{sub 0.6}CoO{sub 2.85} sample exhibit two Schottky anomalies. These anomalies are thought to be related to the high-spin state of the Co{sup 3+} ions in the pyramidal environment caused by oxygen deficiency and to the magnetic state of oxygen p electrons induced by the doping-assisted generation of a hole in the 2p state. The absence of a noticeable shift in the absorption edge and the presence of two Schottky anomalies support the fact that the charge state of cobalt remains unchanged in the compounds under study.

Authors:
; ; ; ; ;  [1];  [2];  [3];  [4];  [3];  [1]
  1. Russian Academy of Sciences, Kirensky Institute of Physics, Siberian Branch (Russian Federation)
  2. Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation)
  3. Russian Academy of Sciences, Institute of Chemistry and Chemical Technology, Siberian Branch (Russian Federation)
  4. Russian Research Centre “Kurchatov Institute,” (Russian Federation)
Publication Date:
OSTI Identifier:
22750019
Resource Type:
Journal Article
Journal Name:
Journal of Experimental and Theoretical Physics
Additional Journal Information:
Journal Volume: 126; Journal Issue: 2; Other Information: Copyright (c) 2018 Pleiades Publishing, Inc.; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1063-7761
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ABSORPTION SPECTROSCOPY; COBALT IONS; GADOLINIUM IONS; HIGH SPIN STATES; OXIDES; OXYGEN; P STATES; QUANTUM MECHANICS; SPECIFIC HEAT; STRONTIUM IONS; TEMPERATURE DEPENDENCE; X RADIATION; X-RAY SPECTROSCOPY

Citation Formats

Orlov, Yu. S., E-mail: jso.krasn@mail.ru, Dudnikov, V. A., Platunov, M. S., Gorev, M. V., Velikanov, D. A., Kazak, N. V., Gavrilkin, S. Yu., Solov’ev, L. A., Veligzhanin, A. A., Vereshchagin, S. N., and Ovchinnikov, S. G.. Low-Temperature Schottky Anomalies and the Magnetic State of the p Electrons of Oxygen in Substituted Gd{sub 0.4}Sr{sub 0.6}CoO{sub 3–δ} Cobaltites. United States: N. p., 2018. Web. doi:10.1134/S1063776118020036.
Orlov, Yu. S., E-mail: jso.krasn@mail.ru, Dudnikov, V. A., Platunov, M. S., Gorev, M. V., Velikanov, D. A., Kazak, N. V., Gavrilkin, S. Yu., Solov’ev, L. A., Veligzhanin, A. A., Vereshchagin, S. N., & Ovchinnikov, S. G.. Low-Temperature Schottky Anomalies and the Magnetic State of the p Electrons of Oxygen in Substituted Gd{sub 0.4}Sr{sub 0.6}CoO{sub 3–δ} Cobaltites. United States. doi:10.1134/S1063776118020036.
Orlov, Yu. S., E-mail: jso.krasn@mail.ru, Dudnikov, V. A., Platunov, M. S., Gorev, M. V., Velikanov, D. A., Kazak, N. V., Gavrilkin, S. Yu., Solov’ev, L. A., Veligzhanin, A. A., Vereshchagin, S. N., and Ovchinnikov, S. G.. Thu . "Low-Temperature Schottky Anomalies and the Magnetic State of the p Electrons of Oxygen in Substituted Gd{sub 0.4}Sr{sub 0.6}CoO{sub 3–δ} Cobaltites". United States. doi:10.1134/S1063776118020036.
@article{osti_22750019,
title = {Low-Temperature Schottky Anomalies and the Magnetic State of the p Electrons of Oxygen in Substituted Gd{sub 0.4}Sr{sub 0.6}CoO{sub 3–δ} Cobaltites},
author = {Orlov, Yu. S., E-mail: jso.krasn@mail.ru and Dudnikov, V. A. and Platunov, M. S. and Gorev, M. V. and Velikanov, D. A. and Kazak, N. V. and Gavrilkin, S. Yu. and Solov’ev, L. A. and Veligzhanin, A. A. and Vereshchagin, S. N. and Ovchinnikov, S. G.},
abstractNote = {The XANES spectra (X-ray absorption near-edge spectra) at the K edge of Co and the L{sub 3} edge of Gd in polycrystalline Gd{sub 0.4}Sr{sub 0.6}CoO{sub 3–δ} rare-earth oxides with an ordered and disordered distribution of Gd{sup 3+} and Sr{sup 2+} cations over the A sites in the crystal lattice are measured. The results of XANES measurements do not reveal a noticeable shift in the absorption edge with increasing Sr concentration as compared to the GdCoO{sub 3} parent composition. The measured temperature dependences of the heat capacity of polycrystalline ordered and disordered samples and a single-crystal ordered Gd{sub 0.4}Sr{sub 0.6}CoO{sub 2.85} sample exhibit two Schottky anomalies. These anomalies are thought to be related to the high-spin state of the Co{sup 3+} ions in the pyramidal environment caused by oxygen deficiency and to the magnetic state of oxygen p electrons induced by the doping-assisted generation of a hole in the 2p state. The absence of a noticeable shift in the absorption edge and the presence of two Schottky anomalies support the fact that the charge state of cobalt remains unchanged in the compounds under study.},
doi = {10.1134/S1063776118020036},
journal = {Journal of Experimental and Theoretical Physics},
issn = {1063-7761},
number = 2,
volume = 126,
place = {United States},
year = {2018},
month = {2}
}