Mechanochemical synthesis of the low-temperature (B20) phase of FeGe

We have investigated solid-state reactions in an equiatomic mixture of Fe and Ge powders during ball milling in a water-cooled high-energy mill under an argon atmosphere. The mechanical alloying products have been characterized by x-ray diffraction, Mössbauer spectroscopy, and calorimetry. The observed sequence of phase formation correlates with the thermodynamic properties of the iron germanides involved. The alloy prepared by ball milling for 2 h consists entirely of nanocrystallites (?15 nm) of the low-temperature, stable, cubic (B20) phase of FeGe.