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

Abstract

SmCo 5 /Fe nanostructured alloys with 20 wt% Fe, obtained by high-energy ball milling of SmCo 5 and Fe powders, were investigated by 57 Fe Mössbauer spectrometry, x-ray diffraction and tomographic atom probe. The Mössbauer analysis reveals that during the first stages of milling, an interdiffusion of Co and Fe occurs, leading both to the formation of α-Fe(Co) regions in α-Fe and to the introduction of Fe in SmCo 5 regions. Annealing at temperatures up to 650 °C for 0.5 h promotes interdiffusion further leading to the formation of a unique α-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.