Evidence of kinetic arrest in Se doped CoS2

Abstract

Abstract. A systematic study of thermomagnetic irreversibility CoS 1.76 Se 0.24 has been carried out. Our study shows that the resistivity at low temperature can be tuned by cooling in different magnetic fields and the critical field required for paramagnetic (PM) to ferromagnetic (FM) transition varies non-monotonically with temperature. The field induced PM to FM transition results in giant positive magnetoresistance (MR) of about 160% at 5 K. Measurements under CHUF (cooling and heating in unequal magnetic field) protocol show reentrant transition on warming under higher magnetic field (than that applied during cooling). It indicates that the glass like behaviour in this system can be explained in the framework of the kinetic arrest of first order transition. Among the growing list of diverse system showing glass like arrested magnetic states, the present system is the first example where, kinetic arrest is observed for a disordered (here PM) to ordered (here FM) first order transition.

Giant negative magnetoresistance and kinetic arrest of first-order ferrimagnetic-antiferromagnetic transition in Ge doped Mn2Sb

“…Similar resistivity behavior has been reported for Co doped Mn 2 Sb, 10 Pd doped FeRh, 36,37 Al or Ru doped CeFe 2 , 38,39 Se doped CoS 2 . 40 In these system it has been attributed to kinetic arrest of the first order transition i.e. at low temperatures due to slow dynamics of the transition, the transformation from high temperature state to low temperature state is hindered on experimental time scale.…”

“…44 The positive slope for lower critical field is dictated by the kinetics of the transition and it is represented as kinetic arrest band (H K , T K ). [36][37][38]40,41,44 The left side of (H K , T K ) band is the region where, kinetics of the transition dominates and FRI phase in this region will not be able to transform back to AFM state due to slow dynamics. Therefore a field induced FRI phase in this temperature region will not transform back to AFM state with decrease in magnetic field resulting in open loop in MR.…”