High-throughput screening of strong electron-phonon couplings in ternary metal diborides

TL;DR

This study uses high-throughput computational screening to identify ternary metal diborides with strong electron-phonon coupling, revealing promising superconducting candidates like Li3ZrB8 and Ca3YB8.

Contribution

It introduces a large-scale computational approach to discover new superconducting materials within ternary metal diborides.

Findings

43 compounds exhibit higher electron-phonon coupling than MgB2.

Identified 17 ground states and 78 metastable phases.

Li3ZrB8 and Ca3YB8 are promising superconducting candidates.

Abstract

We perform a high-throughput screening on phonon-mediated superconductivity in ternary metal diboride structure with alkali, alkaline earth, and transition metals. We find 17 ground states and 78 low-energy metastable phases. From fast calculations of zone-center electron-phonon coupling, 43 compounds are revealed to show electron-phonon coupling strength higher than that of MgB2. An anti-correlation between energetic stability and electron-phonon coupling strength is identified. We suggest two phases, i.e., Li3ZrB8 and Ca3YB8, to be synthesized, which show reasonable energetic stability and superconducting critical temperature.