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

The structure, Curie temperature, and magnetization of (Fe1-xCox)(84)Zr3.5N b3.5B8Cu1 (x = 0.0-0.8) alloys were investigated by x-ray diffractometer, d ifferential scanning calorimeter, magnetic balance, and extracting sample m agnetometer, respectively. The bcc grains are embedded in the amorphous mat rix after controlled annealing. The crystallization temperature T-x of the amorphous alloy decreases with the increasing Co content, whereas the Curie temperature T-c of the amorphous alloy is enhanced by an increase in Co co ntent. The magnetization measured under the field of 60 kOe at a temperatur e 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. (C) 1999 American Institute of Physics. [S0021-8979(99)04522-3].