Mossbauer effect study of magnetic properties of Fe1-qAlq, 0<q⩽0.5, alloys in the disordered phase

Abstract
The authors report the experimental study by Mossbauer spectroscopy, at room temperature (RT), of Fe-Al alloys in the disordered phase, with an Al concentration q in the range 0<q<or=0.5. The alloys are all ferromagnetic and from the fitting of the Mossbauer spectra with hyperfine field (HF) distribution, they obtained the dependence of the average HF with q. It decreases gradually with increasing q and reaches zero at a critical concentration of 47.5 at.% Al. The HF distributions show peaks equally spaced Delta H=24 kOe apart. This value corresponds to the reduction in the average magnetic field due to the substitution of one nearest-neighbour Fe by an Al atom. The magnetic ordering temperatures were obtained and compared with theoretical results.