Chemical Trend of Superconducting Transition Temperature in Hole-doped Delafossite of CuAlO_2, AgAlO_2 and AuAlO_2

TL;DR

This study uses first-principles calculations to predict the superconducting transition temperatures of hole-doped delafossite materials CuAlO_2, AgAlO_2, and AuAlO_2, revealing a trend related to their chemical composition.

Contribution

It provides the first theoretical predictions of T_c for these materials and explains the differences based on electron-phonon interactions and atomic properties.

Findings

CuAlO_2 T_c ~50 K

AgAlO_2 T_c ~40 K

AuAlO_2 T_c ~3 K

Abstract

We have performed the first-principles calculations about the superconducting transition temperature T_c of hole-doped delafossite CuAlO_2, AgAlO_2 and AuAlO_2. Calculated T_c are about 50 K(CuAlO_2), 40 K(AgAlO_2) and 3 K(AuAlO_2) at maximum in the optimum hole-doping concentration. The low T_c of AuAlO_2 is attributed to the weak electron-phonon interaction caused by the low covalency and heavy atomic mass.