Phase Evolution and Magnetic Characteristic of Fe64Co16Zr10B10 Amorphous Alloy.

Fe64Co16Zr10B10 amorphous alloy prepared by a single roller melt spinning was annealed under isothermal treatment at temperatures ranging from 550 to 650°C in a vacuum. Phase evolution and magnetic characteristic of Fe64Co16Zr10B10 amorphous alloy were investigated in detail by combining X-ray diffraction, transmission electron microscopy, scanning transmission electron microscopy/energy dispersive spectroscopy, and vibrating sample magnetometer. At 550°C, the metastable intermediate β-Mn type phase precipitates, as well as an β-Fe(Co) phase. At 575°C, only metastable β-Mn type phase is observed. Scanning transmission electron microscopy/energy dispersive spectroscopy indicates that the β-Mn type nanocrystals contain Fe, Co, and Zr. More Zr is at the interface between the nanocrystals and the amorphous matrix. There is little change in Co concentration among the remaining amorphous matrix, the nanocrystals, and the interface between the nanocrystals and the amorphous matrix. With a further increase in annealing temperature, the crystallization volume fraction of the β-Mn type phase decreases, and the crystallization volume fraction of the β-Fe(Co) phase increases accordingly. Coercivity of Fe64Co16Zr10B10 alloy undergoes a sharp rise above 550°C and a sharp decline above 600°C. [ABSTRACT FROM AUTHOR]