Observation of inverted hysteresis loop and thermomagnetic irreversibility in the antiferromagnetic Mn5Si3 alloy

Abstract

${\mathrm{Mn}}_{5}{\mathrm{Si}}_{3}$ crystallizes in hexagonal ${\mathrm{D}8}_{8}$ type structure (space group $P{6}_{3}/mcm$) with two distinct crystallographic sites for Mn atoms. It undergoes two first-order phase transitions during cooling from paramagnetic to collinear antiferromagnetic phase around 100 K and subsequently to noncollinear antiferromagnetic phase around 66 K. Detailed investigation by dc magnetic measurements probe the presence of inverted hysteresis loop below 66 K. In addition, thermomagnetic and field-induced arrest are the two key features of this alloy. Such arrest of high temperature phase plays the pivotal role toward the observation of inverted hysteresis loop behavior. The robustness of the arrested states was checked by magnetic relaxation measurements.