Magnetic Properties and GMR Effect in Nonequilibriun Co-Cu Alloys Produced by Mechanical Alloying

Abstract

Co20Cu80 binary alloy is produced by mechanical alloying. The magnetoresistance (MR) and magnetic properties in temperature range from 5K to 300K, have been investigated for the as-milled and annealed alloys. The MR for the as-milled sample measured at the temperatures below 120K is not proportional to the square of magnetization M2. However, the MR for the annealed sample changes almost following M2 even below this temperature. With decreasing temperature, the MR ratio for the as-milled sample slightly increases and becomes a constant value of about 3% below 180K, and for the annealed sample monotonously increases and shows about 14% at 5K.