Lattice dynamics and electron-phonon coupling in transition metal diborides

TL;DR

This study measures phonon density-of-states in transition metal diborides using neutron scattering and confirms ab initio calculations, providing insights into electron-phonon interactions relevant for superconductivity.

Contribution

It provides experimental phonon data for TMB2 compounds and validates ab initio calculations, enabling analysis of electron-phonon coupling in these materials.

Findings

Excellent agreement between experiment and theory

Calculated electron-phonon spectral functions are reliable

Comparison with MgB2 and AlB2 highlights superconducting parameters

Abstract

The phonon density-of-states of transition metal diborides TMB2 with TM = Ti, V, Ta, Nb and Y has been measured using the technique of inelastic neutron scattering. The experimental data are compared with ab initio density functional calculations whereby an excellent agreement is registered. The calculations thus can be used to obtain electron-phonon spectral functions within the isotropic limit. A comparison to similar data for MgB2 and AlB2 which were subject of prior publications as well as parameters important for the superconducting properties are part of the discussion.