Study of structural and magnetic properties of (Fe_(100-x)Co_x)_(73.5)Si_(13.5)B_9Nb_3Cu_1 alloys

摘要

The influence of Co addition on structural and magnetic properties of nanocrystalline (Fe_(100-x)Co_x)_(73.5) Si_(13.5)B_9Nb_3Cu-1 (x = 10, 20, 30, 40, 50, 80) alloys has been studied using DSC, Moessbauer spectrometry, XRD and magnetic measurements. Results show that a Fe_(70)Co_(30)-like nano-phase containing a small amount of Si precipitate in Co-rich alloys (x ≥ 30), whereas other alloys exhibits the characteristics of DO_3 FeSi nanoparticles containing a small amount of Co. Exception is found for equi-atomic alloy (x = 50), which decomposes into two phases having different Si content. This drastic change of microstructure for x ≥ 30 directly affects the magnetic properties because of the precipitation of a harder magnetic phase compared with alloys having a low Co content.