Stability of Metallic Structure in Compressed Solid GeH4

TL;DR

This study uses density functional theory to investigate the stability and properties of compressed solid germane, revealing a stable metallic phase with potential high-temperature superconductivity between 23 and 177 GPa.

Contribution

It identifies a new stable metallic phase of solid GeH4 under high pressure and predicts its superconducting properties, expanding understanding of hydrogen-rich superconductors.

Findings

Stable metallic Aba2 phase exists from 23 to 177 GPa.

Predicted higher superconducting transition temperature than SiH4.

Insulator to metal transition occurs around 23 GPa.

Abstract

We study the electronic and lattice dynamical properties of compressed solid germane in the pressure range up to 200 GPa with density functional theory. A stable metallic structure, Aba2, with a base-centered orthorhombic symmetry was found to be the lowest enthalpy phase for pressure from 23 to 177 GPa, suggesting an insulator to metal phase transition around 23 GPa. The Aba2 structure is predicted to have higher superconducting transition temperature than SiH4 reported recently, thus presenting new possibilities for exploring high temperature superconductivity in this hydrogen-rich system.