Low-temperature hysteresis broadening emerging from domain-wall creep dynamics in a two-phase competing system

TL;DR

This study reveals that low-temperature hysteresis broadening in magnetic phase transitions arises from an activated domain-wall creep process, with real-space imaging and modeling providing a quantitative microscopic understanding.

Contribution

It demonstrates that hysteresis broadening is due to activated domain-wall creep, supported by real-space imaging and a combined theoretical model, offering a quantitative microscopic explanation.

Findings

Hysteresis broadening emerges from activated domain-wall creep.

Real-space magnetic imaging confirms the activated behavior.

Modeling reproduces hysteresis and transition field dependence.

Abstract

Hysteretic behaviour accompanies any first-order phase transition, forming a basis for many applications. However, its quantitative understanding remains challenging, and even a qualitative understanding of pronounced hysteresis broadening at low temperature, which is often observed in magnetic-field-induced first-order phase transition materials, is unclear. Here, we show that such pronounced hysteresis broadening emerges if the phase-front velocity during the first-order phase transition exhibits an activated behaviour as a function of both temperature and magnetic field. This is demonstrated by using real-space magnetic imaging techniques, for the magnetic-field-induced first-order phase transition between antiferromagnetic and ferrimagnetic phases in (Fe$_{0.95}$Zn$_{0.05}$)$_{2}$Mo$_{3}$O$_{8}$. When combined with the Kolmogorov-Avrami-Ishibashi model, the observed activated temperature- and field-dependences of the growth velocity of the emerging antiferromagnetic domain quantitatively reproduce the pronounced hysteresis broadening. Furthermore, the same approach also reproduces the field-sweep-rate dependence of the transition field observed in the experiment. Our findings thus provide a quantitative and comprehensive understanding of pronounced hysteresis broadening from the microscopic perspective of domain growth.