Effects of Co addition on magnetic properties and nanocrystallization in amorphous Fe84Zr3.5Nb3.5B8Cu1 alloy

Abstract

The structure, Curie temperature, and magnetization of (Fe1−xCox)84Zr3.5Nb3.5B8Cu1 (x=0.0–0.8) alloys were investigated by x-ray diffractometer, differential scanning calorimeter, magnetic balance, and extracting sample magnetometer, respectively. The bcc grains are embedded in the amorphous matrix after controlled annealing. The crystallization temperature Tx of the amorphous alloy decreases with the increasing Co content, whereas the Curie temperature Tc of the amorphous alloy is enhanced by an increase in Co content. The magnetization measured under the field of 60 kOe at a temperature of 1.5 K is enhanced first by the increase of Co addition, and exhibits a maximum at the composition where x=0.2, then decreases while Co content increases.