Influence of segregation on magnetic order in Cr75(Fe x Mn1−x)25, 0.64 ≤x ≤ 0.85

Mossbauer and magnetic measurements on Cr75(Fe,Mn)25 alloys, which were segregated and re-disordered by appropriate heat treatments, are reported. A primary factor for the kind of magnetic order which appears is the Cr concentration around the Mossbauer probe atom. At around 15 K, a transition to a re-entrant spin-glass state occurs. For this state, the hyperfine field distributions of all investigated disordered and re-disordered samples are independent of the Fe concentration.