First-principles calculations of a high-pressure synthesized compound PtC

TL;DR

This study uses first-principles density-functional calculations to analyze the structural phases of PtC, revealing a pressure-induced phase transition and potential structural changes upon pressure release.

Contribution

It provides the first theoretical confirmation of the zinc-blende ground state and the transition pressure to rock-salt structure in PtC.

Findings

Zinc-blende is the ground-state phase at zero pressure.

Transition pressure from zinc-blende to rock-salt is 52 GPa.

Possible phase transition from rock-salt to zinc-blende upon pressure quench.

Abstract

First-principles density-functional method is used to study the recently high-pressure synthesized compound PtC. It is confirmed by our calculations that the platinum carbide has a zinc-blende ground-state phase at zero pressure and the rock-salt structure is a high-pressure phase. The theoretical transition pressure from zinc-blende to rock-salt is determined to be 52GPa. Furthermore, our calculation shows the possibility that the experimentally synthesized PtC by Ono et al. under high pressure condition might undergo a transition from rock-salt structure to zinc-blende after the pressure quench to ambient condition.