Ab initio study of noncentrosymmetric transition-metal monogermanide B20-RhGe synthesized at high temperature and pressure

TL;DR

This study uses ab initio density-functional calculations to explore the properties and stability of the noncentrosymmetric B20-RhGe phase, providing insights for its synthesis at high pressures and temperatures.

Contribution

It offers a comprehensive theoretical analysis of B20-RhGe's structural, electronic, and thermodynamic properties, guiding experimental synthesis conditions.

Findings

B20-RhGe is stable within specific pressure and temperature ranges.

The study predicts electronic and transport properties of B20-RhGe.

Recommendations are provided to optimize synthesis and reduce defects.

Abstract

We present ab initio density-functional study of the noncentrosymmetric B20-type phase of RhGe, which is not found in nature and can be synthesized only at extreme pressures and temperatures. The structural, thermodynamic, electronic, lattice-dynamical, and transport properties of B20-RhGe are calculated, and their evolution with increasing pressure is traced. The temperature dependence of the charge and heat transport properties is evaluated within the semi-classical Boltzmann approach. Using the quasi-harmonic approximation, we determine the range of pressures and temperatures, in which B20-RhGe is stable, and make recommendations for optimizing the synthesis conditions in order to reduce the number of defects that occur in a sample during solidification.