Magnetic phase diagram of sigma-phase Fe55Re45 compound in the H-T coordinates

TL;DR

This study maps the magnetic phase diagram of sigma-phase Fe55Re45 using DC and AC magnetization measurements, revealing re-entrant magnetism and differences in phase transitions within the H-T plane.

Contribution

It provides the first detailed magnetic phase diagram of Fe55Re45 in the H-T plane, highlighting re-entrant magnetism and differences between DC and AC measurement results.

Findings

Evidence of re-entrant magnetism in Fe55Re45

Identification of two cross-over transitions in the spin-glass state via DC measurements

Single transition observed in AC susceptibility measurements

Abstract

In-field DC and AC magnetization measurements were carried out on a sigma-phase Fe55Re45 intermetallic compound aimed at determination of the magnetic phase diagram in the H-T plane. Field cooled, M_FC, and zero-field cooled, M_ZFC, DC magnetization curves were measured in the magnetic field, H, up to 1200 Oe. AC magnetic susceptibility measurements were carried out at a constant frequency of 1465 Hz under DC fields up to H=500 Oe. The obtained results provide evidences for re-entrant magnetism in the investigated sample. The magnetic phase diagrams in the H-T plane have been outlined based on characteristic temperatures determined from the DC and AC measurements. The phase diagrams are similar yet not identical. The main difference is that in the DC diagram constructed there are two cross-over transitions within the strong-irreversibility spin-glass state, whereas in the AC susceptibility based diagram only one transition is observed. The border lines (irreversibility, cross-over) can be described in terms of the power laws.