Unusual coercivity and zero field stabilization of fully saturated magnetization in single crystals of LaCrGe$_3$

TL;DR

This study reveals unusual coercivity and zero-field stabilization of saturated magnetization in LaCrGe$_3$, showing sharp magnetization reversals and temperature-dependent coercivity in a bulk ferromagnetic crystal.

Contribution

It uncovers a novel magnetic behavior in LaCrGe$_3$, demonstrating sharp, temperature-dependent coercivity and complete magnetization reversals in a bulk crystal, previously seen only in nanocrystalline materials.

Findings

LaCrGe$_3$ exhibits low-temperature coercivity with sharp magnetization reversals.

Coercivity varies with temperature, disappearing between 40-55 K and reappearing near 70-85 K.

Magnetic behavior resembles micromagnetic/nanocrystalline materials, unusual for bulk samples.

Abstract

LaCrGe$_3$ is an itinerant, metallic ferromagnet with a Curie temperature ($T_C$) of $\sim$ 86 K. Whereas LaCrGe$_3$ has been studied extensively as a function of pressure as an example of avoided ferromagnetic quantum criticality, questions about its ambient pressure ordered state remain; specifically, whether there is a change in the nature of the ferromagnetically ordered state below $T_C$ $\sim$ 86 K. We present anisotropic $M$($H$) isotherms, coupled with anisotropic AC susceptibility data, and demonstrate that LaCrGe$_3$ has a remarkable, low temperature coercivity associated with exceptionally sharp, complete magnetization reversals to and from fully polarized states. This coercivity is temperature dependent, it drops to zero in the 40 - 55 K region and reappears in the 70 - 85 K regions. At low temperatures LaCrGe$_3$ has magnetization loops and behavior that has previously associated with micromagnetic/nanocrystalline materials, not bulk, macroscopic samples.