Study of spin fluctuations in Ni3Al using point contact Andreev reflection spectroscopy

TL;DR

This study uses point contact Andreev reflection spectroscopy to investigate how spin fluctuations affect superconducting properties in Ni3Al near its magnetic phase boundary.

Contribution

It demonstrates that PCAR spectroscopy can effectively probe spin fluctuations in materials close to magnetic instability.

Findings

Superconducting quasiparticle lifetime decreases with increased spin fluctuations.

Superconducting energy gap diminishes as spin fluctuations grow.

PCAR is a useful tool for studying spin fluctuations near magnetic phase transitions.

Abstract

We report point contact Andreev reflection (PCAR) spectroscopy studies on Ni3Al with composition range (24, 26 and 27 at. % of Al in the solid solution) spanning the ferromagnetic to paramagnetic phase boundary. PCAR studies performed using Nb tip as counter electrode reveal that the superconducting quasiparticle lifetime (\tao) and superconducting energy gap (\delta) decreases with increasing spin fluctuation in the normal metal electrode. Our study reveals that PCAR could be a useful probe to study spin fluctuations in systems which are on the verge of a magnetic instability.