Ta doping effect in Co/sub 60/C/sub 40/ thin films

(Co/sub 60/C/sub 40/)/sub 1-x/Ta/sub x/ films (03%) destroys the Co structure and this causes the drop in both H/sub c/ and M/sub s/. After annealing at 300(degree)C, H/sub c/ of (Co/sub 60/C/sub 40/)/sub 97/Ta/sub 3/ films increases from 0 to about 380 Oe, while almost no changes are observed for Co/sub 60/C/sub 40/ films. Doping in a Co-C system with a larger atom such as Ta may be a way to enhance the segregation of Co and C and, therefore, reduce phase segregation temperature.