Low compressible noble metal carbides with rock-salt structure: ab initio total energy calculations of the elastic stability

TL;DR

This study uses ab initio calculations to identify noble metal carbides with rock-salt structure that are mechanically stable and metallic, highlighting RuC, PdC, AgC, and PtC as stable candidates with high bulk modulus.

Contribution

The paper systematically evaluates the elastic stability of noble metal carbides with rock-salt structure using density functional theory, identifying four stable compounds and analyzing their properties.

Findings

Only four noble metal carbides are mechanically stable: RuC, PdC, AgC, PtC.

RuC, PdC, and PtC exhibit very high bulk modulus.

These stable carbides are metallic according to density of states analysis.

Abstract

We have systematically studied the mechanical stability of all noble metal carbides with the rock-salt structure by calculating their elastic constants within the density function theory scheme. It was found that only four carbides (RuC, PdC, AgC and PtC) are mechanically stable. In particular, we have shown that RuC, PdC, and PtC have very high bulk modulus, which has been remarkably observed by the most recent experiment for the case of PtC. From the calculated density of states, we can conclude that these compounds are metallic, like the conventional group IV and group V transition metal carbides.