Low temperature study of field induced antiferro-ferromagnetic transition in Pd doped FeRh

TL;DR

This study investigates the low-temperature behavior of the magnetic phase transition in Pd-doped FeRh under high magnetic fields, revealing slow dynamics, history dependence, and phase coexistence phenomena.

Contribution

It provides new insights into the non-monotonic critical field variation and phase coexistence in FeRh at low temperatures under high magnetic fields.

Findings

Critical slowing down of transition dynamics below 50 K.

History-dependent phase coexistence at low temperatures.

Reentrant transition from glass-like FM to AFM state.

Abstract

The first order antiferromagnetic (AFM) to ferromagnetic (FM) transition in the functional material Fe49(Rh0.93Pd0.07)51 has been studied at low temperatures and high magnetic fields. We have addressed the non-monotonic variation of 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 (CHUF) protocol it is shown that equilibrium state at 6 Tesla magnetic field is AFM state. Glass like 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.