Morphology and magnetic behavior of cobalt rich amorphous/nanocrystalline (Co–Ni)70Ti10B20 alloyed powders

• The effect of milling time on Co49Ni21Ti10B20 composition was investigated.
• The coexistence between nanocrystalline and amorphous phases was observed.
• The magnetic coercivity reached to a low value (≈39 Oe).
• The heat treatment revealed a drastic increment in coercivity value.

The effect of milling time on microstructural and magnetic behavior of mechanically alloyed Co49Ni21Ti10B20 is investigated by using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy, differential scanning calorimetry and vibrating sample magnetometer. It is shown, with increasing milling time, the crystallite size decreases and finally reaches to a low value after 190 h of milling time. The increase in microstrain is also observed during the milling process. The results indicate the coexistence between amorphous and nanocrystalline phases after 190 h of milling time. Moreover, the lowest magnetic coercivity of about 39 Oe at the final milling stage is observed. The results of annealed sample reveal structural ordering of constituent elements.