First order antiferro-ferromagnetic transition in Fe49(Rh0.93Pd0.07)51 under simultaneous application of magnetic field and external pressure

TL;DR

This study maps the magnetic field-pressure-temperature phase diagram of Fe49(Rh0.93Pd0.07)51, revealing how pressure and magnetic field oppositely influence the antiferro-ferromagnetic transition, with implications for understanding first order magnetic transitions.

Contribution

It provides the first detailed phase diagram under simultaneous magnetic field and pressure, showing how these parameters affect transition temperature, hysteresis, and transition width in a disorder-broadened first order transition.

Findings

Transition temperature increases with pressure (~7.3 K/kbar)

Transition temperature decreases with magnetic field (~-12.8 K/Tesla)

Transition width decreases exponentially with temperature

Abstract

The magnetic field-pressure-temperature (H-P-T) phase diagram for first order antiferromagnetic (AFM) to ferromagnetic (FM) transition in Fe49(Rh0.93Pd0.07)51 has been constructed using resistivity measurements under simultaneous application of magnetic field (up to 8 Tesla) and pressure (up to 20 kbar). Temperature dependence of resistivity ({\rho}-T) shows that with increasing pressure, the width of the transition and the extent of hysteresis decreases whereas with the application of magnetic field it increases. Consistent with existing literature the first order transition temperature (TN) increases with the application of external pressure (~ 7.3 K/ kbar) and decreases with magnetic field (~ - 12.8 K/Tesla). Exploiting these opposing trends, resistivity under simultaneous application of magnetic field and pressure is used to distinguish the relative effect of temperature, magnetic field and pressure on disorder broadened first order transition. For this a set of H and P values are chosen for which TN (H1, P1) = TN (H2, P2). Measurements for such combinations of H and P show that the temperature dependence of resistivity is similar i.e. the broadening (in temperature) of transition as well as extent of hysteresis remains independent of H and P. The transition width decreases exponentially with increasing temperature. Isothermal magnetoresistance measurement under various constant pressure show that even though the critical field required for AFM-FM transition depends on applied pressure, the hysteresis as well as transition width (in magnetic field) both remains independent of pressure, consistent with our conclusions drawn from {\rho}-T measurements.