POSTANNEALING EFFECT ON TRANSPORT-PROPERTIES OF CO-PD ALLOY-FILMS

A series of Co-100 Pd-x (x=85-25 at.% Pd) alloy films were made by the vapour deposition method. The film thickness t was set at 400 Angstro m. Some of the films were isothermally annealed for 1 h at various tem peratures T-a in the range 240-400 degrees C. The average grain size D of each film was checked by an X-ray diffractometer and an atomic for ce microscope. The zero-field resistivity rho(0), and the anisotropic magnetoresistance ratio Delta rho/(rho>(0) were measured for each film at room temperature. We have obtained data for D, rho(0), and Delta r ho/rho(0) as a function of T-a. It is concluded that the 1 h anneals o f these films can be divided into two stages: the recovery and the gra in growth. It is also found that although the average grain size is en larged continuously by increasing T-a, the transport properties of the films for a fixed thickness approach their saturated values long befo re the grains stop to grow.