GMR in co-evaporated CoAg granular thin films

We report the magnetic and magnetoresistive behavior of Co x Ag 100− x granular films over a wide range of compositions ( x = 20–80 at%), deposited by oblique co-evaporation at room temperature. The average size of magnetic particles estimated from the magnetization data, assuming a log-normal distribution function, varies with x from 20 to about 50 Å. The GMR variation with x shows a broad maximum at x max = 34 at% at T = 300 K, which increases ∼ 3 times at 10 K while x max shifts to 25 at%.