Structural, elastic, and electronic properties of newly discovered Li2PtSi3 superconductor: Effect of transition metals

TL;DR

This study uses first-principles DFT calculations to predict the structural, elastic, and electronic properties of the newly discovered Li2PtSi3 superconductor and compares it with Li2IrSi3 to understand the effects of transition metal substitution.

Contribution

It provides the first theoretical analysis of Li2PtSi3's properties and examines the impact of replacing Ir with Pt on its superconducting and electronic characteristics.

Findings

Electronic structure is minimally affected by spin-orbit coupling.

Superconducting transition temperature differences are mainly due to electronic density of states.

Li2PtSi3 has a slightly lower Debye temperature than Li2IrSi3.

Abstract

First-principles calculations within the density functional theory (DFT) with GGA-PBE exchange-correlation scheme have been employed to predict the structural, the elastic and the electronic properties of newly discovered lithium silicide superconductor, Li2PtSi3, for the first time. All the theoretical results are compared with those calculated recently for isostructural Li2IrSi3. The present study sheds light on the effect of replacement of transition metal element Ir with Pt on different mechanical, electronic, and superconducting properties. The effect of spin-orbit coupling on electronic band structure was found to be insignificant for Li2PtSi3. The difference in superconducting transition temperatures of Li2PtSi3 and Li2IrSi3 arises primarily due to the difference in electronic energy density of states at the Fermi level. Somewhat reduced Debye temperature in Li2PtSi3 plays a minor role. We have discussed the implications of the theoretical results in details in this study.