Small-angle neutron-scattering studies of reentrant spin-glass behavior in Fe-Al alloys

Abstract

Fe-Al alloys around the concentration of 30 at. % Al show very interesting magnetic properties. Alloys with this concentration present magnetic inhomogeneities and their evolution with temperature is also interesting because they show a reentrant spin-glass behavior at low temperatures. Small-angle neutron-scattering measurements were performed in Fe69.5 Al30.5, Fe70 Al30, and Fe70.5 Al29.5 alloys in the temperature range of 4-300 K. Even though the change in Fe content is very small, the response variation is quite large. The results show that the samples have magnetic inhomogeneities that evolve with temperature. Only in the Fe-richest sample the random-field model can be applied. © 2006 American Institute of Physics.