Superconductivity at 2.2K in La3Ni4P4O2

TL;DR

This paper reports the discovery of superconductivity at 2.2K in La3Ni4P4O2, highlighting its layered structure and conventional superconducting features despite strong normal state susceptibility.

Contribution

It presents the first observation of superconductivity in La3Ni4P4O2 and analyzes its electronic and magnetic properties, revealing a conventional superconducting behavior with enhanced susceptibility.

Findings

Superconductivity observed at 2.2 K in La3Ni4P4O2

Normal state susceptibility is strongly enhanced (Rw ~ 5)

Electronic specific heat coefficient gamma is about 2/3 of layered nickel borocarbides

Abstract

We report the observation of superconductivity in La3Ni4P4O2 at 2.2 K. The layer stacking in this compound results in an asymmetric distribution of charge reservoir layers around the Ni2P2 planes. The estimated Wilson ratio, Rw ~ 5, indicates the presence of a strongly enhanced normal state susceptibility, but many of the basic superconducting characteristics are conventional. The estimated electronic contribution to the specific heat, gamma ~ 6.2 mJ mol-Ni^-1K^-2, is about 2/3 of that found in layered nickel borocarbide superconductors.