A structural investigation of SmCo5/Fe nanostructured alloys obtained by high-energy ball milling and subsequent annealing

SmCo5/Fe nanostructured alloys with 20 wt% Fe, obtained by high-energy ball milling of SmCo5 and Fe powders, were investigated by Fe-57 Mossbauer spectrometry, x-ray diffraction and tomographic atom probe. The Mossbauer analysis reveals that during the first stages of milling, an interdiffusion of Co and Fe occurs, leading both to the formation of alpha-Fe(Co) regions in alpha-Fe and to the introduction of Fe in SmCo5 regions. Annealing at temperatures up to 650 degrees C for 0.5 h promotes interdiffusion further leading to the formation of a unique alpha-Fe(Co) phase and a Fe-richer Sm(Co, Fe)(5) phase. The Co/Fe interdiffusion is confirmed by tomographic atom probe analysis. The data are discussed and compared with the results of previous magnetic measurements.