Electron spin resonance study of the LaIn3-xSnx superconducting system

TL;DR

This study investigates the LaIn3-xSnx superconducting system using Gd3+ ESR measurements, revealing that Sn substitution does not significantly alter the exchange interaction and confirming LaSn3 as a conventional superconductor.

Contribution

The paper provides microscopic ESR evidence that the exchange interaction remains stable across Sn substitution and characterizes LaSn3 as a conventional superconductor.

Findings

Exchange interaction J_fs is nearly unchanged with Sn substitution.

LaSn3 is confirmed as a conventional superconductor.

Superconducting T_c varies oscillatory with Sn content.

Abstract

The LaIn3-xSnx alloy system is composed of superconducting Pauli paramagnets. For LaIn3 the superconducting critical temperature T_c is approximately 0.7 K and it shows an oscillatory dependence as a function of Sn substitution, presenting its highest value T_c ~ 6.4 K for the LaSn3 end member. The superconducting state of these materials was characterized as being of the conventional type. We report our results for Gd3+ electron spin resonance (ESR) measurements in the LaIn3-xSnx compounds as a function of x. We show that the effective exchange interaction parameter J_fs between the Gd3+ 4f local moment and the s-like conduction electrons is almost unchanged by Sn substitution and observe microscopically that LaSn3 is a conventional superconductor.