Evidence of a small crystal field anisotropy in GdCoIn$_5$

TL;DR

This study reveals a small but significant crystal field anisotropy in GdCoIn$_5$, affecting its magnetic properties and lattice behavior under magnetic fields, with implications for understanding its low-energy magnetic interactions.

Contribution

It provides experimental evidence of a subtle crystal field anisotropy in GdCoIn$_5$, highlighting its impact on magnetic susceptibility and lattice responses.

Findings

Susceptibility anisotropy is suppressed by a few Tesla.

Magnetoresistance and magnetostriction show low energy-scale effects.

Lattice length changes abruptly below 2 Tesla when field is perpendicular to c-axis.

Abstract

We investigate the effects of an applied magnetic field on the magnetic properties of the antiferromagnet GdCoIn$_5$. The prominent anisotropy observed in the susceptibility below $T_N$ is rapidly suppressed by a field of just a few Tesla. Further evidence of this low energy-scale is obtained from magnetoresistance and magnetostriction experiments. The lattice lenght, particulary, shows a sudden change below 2 Tesla when the magnetic field is applied perpendicular to the crystallographic $\hat{c}$-axis. The experimental results as a whole can be attributed to a small but non negligible higher-order crystalline electric field.