MAGNETISM AND MAGNETORESISTIVE PROPERTIES IN FEXCU100-X ALLOYS PRODUCED BY MECHANICAL ALLOYING

Metallic granular FexCu100-x alloys with Fe concentration of x = 10-90 are prepared by mechanical alloying (MA). The alloy structure, magnet oresistance (MR), and magnetism have been investigated for as-milled a nd annealed samples. After milling for 50 h; the samples consist of a supersaturated solid solution of single fee phase over the wide Fe con centration range x = 10-60. The magnetization of the as-milled samples deviates downward from a simple dilution law: decreases with decreasi ng x and vanishes at x similar or equal to 20. The maximum MR ratio, u nder 15 kOe at room temperature, is 1.2% for the sample with x = 28 an nealed at 250 degrees C for Ih. The samples with x = 18-28 show reentr ant spin-glass-like behavior. However, the samples with x greater than 25 show ferromagnetic behavior at room temperature.