Monte Carlo Simulation of Kerr Effect and Giant Magnetoresistance in Co_xAg_1-x Granular Films

Based on the Monte Carlo simulation, we present the theoretical calculation of the Kerr loops and giant magnetoresistance (GMR) curves in Co_xAg_1-x granular films. The calculated results of both the Kerr loops and the GMR curves are in good agreement with the experimental ones. The anisotropy energy and the dipolar interaction evidently influence the Kerr loops and the GMR effect and it is found that with the increasing Co content X, the value of anisotropy constant K decreases and the value of dipolar interaction constant D increases. The values of K_t for the Co_XAg_1-X granular films are calculated, which plays an important role in explaining the GMR effect of the granular films. Here K_t is a parameter related to the resistivity at zero field and to the scattering parameter constant.