Magnetic behaviour of Y(FexAl1-x)2alloys

Abstract

Magnetic and ⁵⁷Fe Mossbauer measurements are reported for Y(Fe_xAl_1-x)₂, 0<x<or=0.8. The mean effective moment per Fe atom is only mildly dependent on concentration. In contrast, the mean spontaneous moment decreases rapidly and the long-range ferromagnetic order disappears at about x=0.78. For lower iron content short-range order and freezing effects are observed, typical for mictomagnetism. The low-temperature data were interpreted as the sum of a susceptibility and of a field-dependent magnetisation caused by magnetic clusters originating from the statistical replacement of Al for Fe. These clusters exist throughout the whole concentration range. From both magnetic and Mossbauer measurements indications for the presence of Fe moments were obtained even at high dilution.