Suppression of Pressure-Induced Phase Transitions in a Monoclinically Distorted LiNbO3-Type CuNbO3 by Preference for a CuO3 Triangular Coordination Environment

Masayuki Fukuda; Hidenobu Murata; Takumi Nishikubo; Qiumin Liu; Koomok Lee; Takehiro Koike; Yuma Takahashi; Saori I Kawaguchi; Naohisa Hirao; Hiroshi Funakubo; Masaki Azuma

doi:10.1021/acs.inorgchem.2c01766

Suppression of Pressure-Induced Phase Transitions in a Monoclinically Distorted LiNbO₃-Type CuNbO₃ by Preference for a CuO₃ Triangular Coordination Environment

Inorg Chem. 2022 Aug 15;61(32):12719-12725. doi: 10.1021/acs.inorgchem.2c01766. Epub 2022 Aug 3.

Authors

Masayuki Fukuda¹, Hidenobu Murata², Takumi Nishikubo^{1

3}, Qiumin Liu¹, Koomok Lee¹, Takehiro Koike¹, Yuma Takahashi⁴, Saori I Kawaguchi⁵, Naohisa Hirao⁵, Hiroshi Funakubo⁴, Masaki Azuma^{1

3}

Affiliations

¹ Laboratory for Materials and Structures, Tokyo Institute of Technology, Midori-ku, Yokohama 226-8503, Japan.
² Department of Materials Science, Graduate School of Engineering, Osaka Prefecture University, Sakai 599-8531, Japan.
³ Kanagawa Institute of Industrial Science and Technology, Ebina 243-0435, Japan.
⁴ Department of Materials Science and Engineering, Tokyo Institute of Technology, Yokohama 226-8502, Japan.
⁵ Japan Synchrotron Radiation Research Institute (JASRI), Sayo, Hyogo 679-5198, Japan.

PMID: 35921586
DOI: 10.1021/acs.inorgchem.2c01766

Abstract

Pressure-induced phase transitions in a monoclinically distorted LiNbO₃-type CuNbO₃ with triangularly coordinated Cu and octahedrally coordinated Nb were experimentally and computationally investigated. Phase transitions into GdFeO₃-type or NaIO₃-type structures generally observed in LiNbO₃-type compounds below 30 GPa were not detected in CuNbO₃ even at the maximum experimental pressure, 32.4 GPa. Our density functional theory calculations revealed that the phase transition is suppressed by the preference for the CuO₃ triangular coordination environment, which reduces the total internal energy. This study clarifies that the change in the coordination environment of given ions can affect the pressure-induced phase transition.