Antisite disorder driven cluster glass state and colossal magnetoresistance in MnSb2Se4
Antisite disorder plays a significant role in determining the ground state of a magnetic material. The ternary chalcogenide material MnSb2Se4 with ∼26% antisite disorder between Mn and Sb sites is known to be an antiferromagnet (TN = 22.5 K) and a type-II mulitferroic. In this paper, we report the effect of increased antisite disorder (∼40%) on the magnetic and electrical transport properties of this compound. Magnetic susceptibility and heat-capacity measurements indicate the absence of long-range magnetic ordering. Furthermore, AC susceptibility measurements unfold its nonequilibrium magnetic dynamics at low temperatures. Data analysis with various dynamic scaling models, namely, power law, Arrhenius law, and Vogel-Fulcher confirm a cluster glass state. Moreover, the presence of magnetic memory effect and magnetic relaxation reveal the nonequilibrium dynamics of the system through many metastable states. In addition, a negative colossal magnetoresistance is observed below the freezing temperature due to competing ferromagnetic and antiferromagnetic interactions induced by increased antisite disorder. These results indicate that MnSb2Se4 is a new addition to a very small group of chalcogenides which show negative colossal magnetoresistance.
