Spin Polarization Transport in Thin Magnetic Film

Abstract

The idea of Johnson and Silsbee concerning the existence of coupling between electronic charge and spin at an interface between a ferromagnetic and paramagnetic metal is in the presented work considered in the case of thin ferromagnetic films. Spin polarization transport is analysed in films with crystalline structure as well as in amorphous materials with various types of exchange integral distribution functions. The spin relaxation time has been calculated for thin films above the Curie temperature first in the molecular field approximation and then in the frame of Ising model with the accuracy to the third Matsudaira approximation. In the case of amorphous films the Handrich-Kaneyoshi and Gaussian distribution of exchange integrals have been examined. As a result the asymmetric countours of constant signal have been obtained for crystalline films and binary diluted alloys considered in third Matsudaira approximation. It was shown that the shape of contours depends on the concentration of magnetic atoms in the case of diluted alloy and on the choice of the exchange integral distribution function in the case of amorphous films.