A Mِssbauer investigation of the formation of the Ni3Fe phase by high energy ball milling and subsequent annealing

Ni–Fe alloys obtained by high energy ball milling of pure Ni and Fe powders were investigated by 57Fe Mössbauer spectrometry. The Mössbauer spectra of the as-milled powders were fitted with two magnetic contributions, corresponding to the α-Fe and Ni–Fe phases. As the milling time increases, the relative intensity of the α-Fe contribution decreases while that of the Ni–Fe phase increases. After about 10 h of milling, a Ni–Fe phase with a composition close to Ni3Fe is obtained and no more α-Fe phase is present in the powder. The contribution of the Ni–Fe phase is carefully investigated, and the value of the hyperfine field shows that Ni3Fe is formed in a disordered state. The influence of an annealing treatment at 330 °C is discussed and compared to the results of both X-ray diffraction analysis and magnetic measurements previously obtained.