Effect of Doping on the phase stability and Superconductivity in LaH10

TL;DR

This study computationally explores how doping LaH10 with various elements affects its phase stability and superconducting properties, revealing Ce as a promising dopant for stabilizing high-temperature superconductivity at lower pressures.

Contribution

It identifies Ce as an effective dopant that stabilizes LaH10 and maintains superconductivity, offering new insights into doping strategies for high-temperature superconductors.

Findings

Most dopants soften phonon modes, enhancing electron-phonon coupling.

Ce doping extends dynamical stability and maintains superconductivity.

Doping configurations have minimal impact on stability and coupling.

Abstract

We present a computational investigation into the effects of chemical doping with 15 different elements on phase stability and superconductivity in the LaH10 structure. Most doping elements were found to induce softening of phonon modes, enhancing electron-phonon coupling and improving critical superconducting temperature while weakening dynamical stability. Unlike these dopants, Ce was found to extend the range of dynamical stability for LaH10 by eliminating the van Hove singularity near the Fermi level. The doped compound, La0.75Ce0.25H10, maintains high-temperature superconductivity. We also demonstrate that different Ce doping configurations in the LaH10 structure have a minimal effect on energetic stability and electron-phonon coupling strength. Our findings suggest that Ce is a promising dopant to stabilize LaH10 at lower pressures while preserving its high-temperature superconductivity.