Theoretical Study of Electron-Phonon Interaction in ZrB2 and TaB2

TL;DR

This theoretical study uses density-functional methods to analyze electron-phonon interactions in ZrB2 and TaB2, revealing weak coupling in ZrB2 and potential superconductivity in TaB2 with a transition temperature around 12 K.

Contribution

It provides the first detailed theoretical comparison of electron-phonon interactions in ZrB2 and TaB2 using first-principles calculations.

Findings

Weak electron-phonon coupling in ZrB2 (λ=0.14)

Stronger coupling in TaB2 (λ=0.72)

Superconductivity predicted in TaB2 with Tc ~12 K

Abstract

Using full-potential, density-functional-based methods we have studied electron-phonon interaction in ZrB2 and TaB2 in P6/mmm crystal structure. Our results for phonon density of states and Eliashberg function show that the electron-phonon coupling in ZrB2 is much weaker than in TaB2. In particular, we find that the average electron-phonon coupling constant \lambda is equal to 0.14 for ZrB2 and 0.72 for TaB2. The solutions of the isotropic Eliashberg gap equation indicate no superconductivity for ZrB2 but a superconducting transition temperature Tc of around 12 K for TaB2 with \mu* ~0.16.