Strong enhancement of magnetic coercivity induced by uniaxial stress

TL;DR

This study demonstrates that applying uniaxial stress to a heavy-fermion ferromagnet significantly increases its magnetic coercivity by inducing defects that pin domain walls, with potential applications in magnetic material enhancement.

Contribution

We reveal that uniaxial stress can dramatically enhance coercivity in ferromagnets through defect formation, offering a new method to improve magnetic performance.

Findings

Coercivity increased by 2400% under ~1 kbar stress

Magnetic properties like ordering temperature are weakly affected and reversible

Stress-induced defects effectively pin domain walls

Abstract

The performance of permanent magnets is intricately tied to their magnetic hysteresis loop. In this study, we investigate the heavy-fermion ferromagnet CeAgSb$_2$ through magnetization measurements under uniaxial stress. We observe a 2400 % increase in magnetic coercivity with just a modest stress of approximately 1 kbar. This effect persists even after pressure release, attributable to stress-induced defects that efficiently pin domain walls. Other magnetic properties such as ordering temperature and saturation moment exhibit only weak pressure dependencies and display full reversibility. Our findings offer a promising route for increasing coercive field strength and enhancing the energy product in ferromagnetic materials and are potentially applicable to a broad spectrum of commercial or emerging magnetic applications.