Is the Re-entrant Magnetic Behaviour of Fe-Alloys Due to Fe-Rich Precipitates?

Abstract

An Au0.85Fe0.15 film (80 nm thick) was prepared by quenching the vapour onto a liquid-helium-cooled substrate and its a.c.-susceptibility χ' was measured in situ. The temperature dependence of χ' obtained after stepwise annealing and recooling indicated a transition to ferromagnetism at Tc = 125 K and a magnetic "re-entrant behaviour" at Tfg = 42 K. Since the above preparation technique hinders the formation of extended Fe-clusters or Fe-rich platelets, it is concluded that such metallurgical clusters are not causing the observed "re-entrant behaviour". Tfg appears to be independent of the frozen-in disorder of the Au-matrix.