Structure, hyperfine interactions and magnetization studies of mechanically alloyed Fe50Ge50 and Fe62Ge38

X-ray diffraction, Mössbauer spectroscopy and magnetization measurements were used to study the structure and some magnetic properties of Fe50Ge50 and Fe62Ge38 prepared by mechanical alloying from the elemental powders. In both cases in the early stages of milling the intermediate paramagnetic FeGe2 phase was formed. The mechanical alloying process of Fe50Ge50 resulted in the formation of the paramagnetic FeGe (B20) phase with an average crystallite size of about 15nm. In the case of the Fe62Ge38, the ferromagnetic Fe5Ge3 (β) phase with a Curie temperature of about 430K was obtained. The average crystallite size was about 9nm. The average hyperfine magnetic field of about 16T allowed it to determine that more than four germanium atoms exist in the nearest environment of the 57Fe isotopes in the Fe5Ge3 phase.