Low-temperature study of field-induced antiferromagnetic-ferromagnetic transition in Pd-doped Fe-Rh

Abstract

The first-order antiferromagnetic (AFM) to ferromagnetic (FM) transition in the functional material Fe₄₉(Rh_0.93Pd_0.07)₅₁ has been studied at low temperatures and high magnetic fields. We have addressed the nonmonotonic variation in lower critical field required for FM to AFM transition. It is shown that critically slow dynamics of the transition dominates below 50 K. At low temperature and high magnetic field, state of the system depends on the measurement history resulting in tunable coexistence of AFM and FM phases. By following cooling and heating in unequal magnetic field protocol it is shown that equilibrium state at 6 T magnetic field is AFM state. Glasslike FM state at 6 T (obtained after cooling in 8 T) shows reentrant transition with increasing temperature; viz., devitrification to AFM state followed by melting to FM state.