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https://doi.org/10.3938/NPSM.67.7
High-Temperature X-ray Powder Diffraction Studies on Perovskite Oxynitrides SrNbO$_2$N and SrTaO$_2$N
New Physics: Sae Mulli 2017; 67: 7~11
Published online January 31, 2017;  https://doi.org/10.3938/NPSM.67.7
© 2017 New Physics: Sae Mulli.

Youngguk SON1, Ilkyoung JEONG*2

1 Department of Physics Education, Pusan National University, Busan 46241, Korea
2 Department of Physics Education & Research Center for Dielectrics and Advanced Matter Physics, Pusan National University, Busan 46241, Korea
Correspondence to: jeong@pusan.ac.kr
Received June 11, 2016; Revised November 4, 2016; Accepted November 4, 2016.
cc This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Perovskite oxynitrides have a ABO$_2$N composition with a partial substitution of nitrogen for oxygen. The nitrogen substitution distorts the BO$_4$N$_2$ octahedra and induces octahedral tilting and displacement of B-site ions, which are responsible for emerging dielectric, magnetic and optical properties. We studied the structural evolutions of SrNbO$_2$N and SrTaO$_2$N by using X-ray powder diffraction measurements from 30 $^{\circ}$C $\sim$ 500 $^{\circ}$C. In the case of SrNbO$_2$N, the width of the Bragg peak increased rapidly at 450 $^{\circ}$C, and the structure underwent a transition to a cubic structure. Similarly, Bragg peak broadening without a structural transition was observed in SrTaO$_2$N from 420 $^{\circ}$C. This study shows that B-site ions play an important role in the structural stability of perovskite oxynitrides at high temperatures.
PACS numbers: 61.43.Gt, 61.05.cp, 77.22.Ch
Keywords: Perovskite oxynitride, X-ray powder diffraction, High-temperature stability


May 2017, 67 (5)