Magnetostostriction of Amorphoias Fe–Y and (Fe–Co) 0.8Y0.2 Alloys

The magnetostriction of Fe1-xYx (0.2≤lx≥0.6) and of (Fe1-x Cox)0 . 8Y0 . 2 (0≤x≥0.6) alloys has been measured in the temperature range from 20 to 300 K. In Fe-Y alloys, the magnetostriction λ is 2.8x10−6 at 20 K when x=0.2, and decreases monotonically with increasing x and temperature. This magnetostriction in FeY alloys is the smallest among all Fe-based amorphous binary alloys investigated so far. In (Fe1 - xCox)0 . 8Y0 . 2 alloys, λ at room temperature shows a minimum of 1.0x10−6 at x–0.3, at which the magnetization and coercive force are 125 emu/g and 0.05 Oe respectively.