Superconductivity in Layered Pnictides BaRh2P2 and BaIr2P2

TL;DR

This paper reports the discovery of bulk superconductivity in layered pnictides BaRh2P2 and BaIr2P2, expanding the family of superconducting transition metal pnictides and characterizing their electronic properties.

Contribution

It presents the first observation of superconductivity in BaRh2P2 and BaIr2P2, highlighting their structural similarity to Fe pnictides and analyzing their electronic characteristics.

Findings

Superconducting transition temperatures of 1.0 K and 2.1 K.

Moderately large electronic density of states.

Absence of strong electron correlations and magnetic fluctuations.

Abstract

Bulk superconductivity was discovered in BaRh2P2 (Tc = 1.0 K) and BaIr2P2 (Tc = 2.1 K), which are isostructural to (Ba,K)Fe2As2, indicative of the appearance of superconductivity over a wide variety of layered transition metal pnictides. The electronic specific heat coefficient gamma in the normal state, 9.75 and 6.86 mJ/mol K2 for BaRh2P2 and BaIr2P2 respectively, indicate that the electronic density of states of these two compounds are moderately large but smaller than those of Fe pnictide superconductors. The Wilson ratio close to 1 indeed implies the absence of strong electron correlations and magnetic fluctuations unlike Fe pnictides.