Ab initio calculations of the physical properties of transition metal carbides and nitrides and possible routes to high-Tc

TL;DR

This paper uses ab initio calculations to analyze the phonon spectra and electron-phonon interactions in transition metal carbides and nitrides, exploring their superconducting properties and potential routes to enhance Tc.

Contribution

It provides detailed ab initio insights into the phonon and electron-phonon properties of transition metal carbides and nitrides, including NbC, and discusses strategies to increase their superconducting critical temperatures.

Findings

Calculated phonon spectra and electron-phonon interactions agree with experiments for NbC.

Normal-pressure properties of NbC match experimental data.

Discussed factors limiting Tc and potential methods to increase it.

Abstract

Ab initio linear-response calculations are reported of the phonon spectra and the electron-phonon interaction for several transition metal carbides and nitrides in a NaCl-type structure. For NbC, the kinetic, optical, and superconducting properties are calculated in detail at various pressures and the normal-pressure results are found to well agree with the experiment. Factors accounting for the relatively low critical temperatures Tc in transition metal compounds with light elements are considered and the possible ways of increasing Tc are discussed.