The influence of annealing on the structural and magnetic properties of the Co/sub 100-x/Ni/sub x/ thin films

摘要

The aim of this work was to study the structure dependence of the magnetic properties of Co/sub 100-x/Ni/sub x/ (x=20, 40, 50, 60) microcrystalline thin films prepared by the flash-evaporation technique. The grain size of the microcrystalline phase depends on the concentration of Ni. The domain structure which was studied by Lorentz transmission electron microscopy (LTEM) depends on the size of microcrystals and its character corresponds to that of the thin films which are suitable for longitudinal recording. The influence of annealing on the structure and the magnetic properties was studied. The annealing at temperatures above 350/spl deg/C transformed the microcrystalline structure of the films into a polycrystalline one. The grain size increased with annealing temperature and decreased with the concentration of Ni. The domain structure of annealed films has been influenced by the structural changes. After annealing at 550/spl deg/C, in addition to the ripple structure, the black and white dots (BWD) type of domain structure typical for perpendicular recording media, was observed. Experimental results obtained by TEM and LTEM were completed by the Hall effect measurements and with temperature and concentration dependencies of saturated magnetic polarization B/sub S/ and the Hall coefficient R/sub 1/.