Competing Ferromagnetic and Spin-Glass Order in a<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>Au</mml:mi><mml:mi mathvariant="normal">Fe</mml:mi></mml:math>Alloy

Abstract

Magnetic and M\"ossbauer measurements on a $\mathrm{Au}$-19-at.%-Fe alloy are reported. After ferromagnetic ordering at ${T}_{c}\ensuremath{\cong}170$ K, spin-glass-like transverse ordering sets in below $T\ensuremath{\cong}60$ K; strong irreversibility in the magnetization process only occurs below $T\ensuremath{\cong}15$ K. This behavior is consistent with the predictions of a Heisenberg mean-field model, in which the transverse ordering transition is distinct from a crossover to strong irreversibility.