Metastability in the ferrimagnetic-antiferromagnetic phase transition in Co substituted Mn₂Sb

Abstract

A detailed investigation of the first-order ferrimagnetic (FRI) to antiferromagnetic (AFM) transition in Mn_1.85Co_0.15Sb is carried out. These measurements demonstrate anomalous thermomagnetic irreversibility and a glass-like frozen FRI phase at low temperatures. The irreversibility arising between the supercooling and superheating spinodals is distinguished in an ingenious way from the irreversibility arising due to kinetic arrest. Field annealing measurements show a re-entrant FRI-AFM-FRI transition with increasing temperature. In this system the kinetic arrest band and supercooling band are also shown to be anticorrelated (i.e. the regions which are kinetically arrested at higher temperature have lower supercooling temperature and vice versa), which has been a universal feature of the AFM/ferromagnetic transition so far.