Phase transition and electronic properties of Co-As binary compounds at high pressure

Ao Zhang; Yaqian Dan; Han Liu; Siyuan Liu; Jincheng Yue; Junda Li; Yanping Huang; Yanhui Liu; Tian Cui

doi:10.1039/d2ra02114e

Phase transition and electronic properties of Co-As binary compounds at high pressure

RSC Adv. 2022 Jun 21;12(28):18102-18106. doi: 10.1039/d2ra02114e. eCollection 2022 Jun 14.

Authors

Ao Zhang^{1

2}, Yaqian Dan¹, Han Liu^{1

2}, Siyuan Liu³, Jincheng Yue¹, Junda Li¹, Yanping Huang¹, Yanhui Liu¹, Tian Cui¹

Affiliations

¹ Institute of High Pressure Physics, School of Physical Science and Technology, Ningbo University Ningbo 315211 China liuyanhui@nbu.edu.cn cuitian@nbu.edu.cn.
² Department of Physics, College of Science, Yanbian University Yanji 133000 China.
³ School of Physics, Southeast University Nanjing 211189 China.

Abstract

New stable stoichiometries in the Co-As system are investigated up to 100 GPa by the CALYPSO structure prediction method. In particular, we found three novel stable compounds of Co₂As-Pnma, CoAs₂-Pnnm, and CoAs₃-C2/m at high pressure. According to the theoretical electronic band structures, the structures of Co₂As-Pnma, CoAs₂-Pnnm, and CoAs₃-C2/m have metallic characters, and a pressure-induced electronic topological transition was found in CoAs₃-C2/m, which is not shown in other stoichiometries of the Co-As system. The calculated results of the electron localization function show that there are polar covalent bond interactions between Co atoms and As atoms in CoAs₂-Pnnm and CoAs₃-C2/m. The present results can be helpful for understanding diverse structures and properties of Co-As binary compounds under high pressure.