(FexCo0.5-x)Pt-0.5 ternary thin films were deposited on glass substrates by
using a dc sputtering method at room temperature and were subsequently ann
ealed at 700 degrees C in a high vacuum. A high degree of the (111) preferr
ed orientation could be obtained in all the as-deposited films and was not
destroyed, even though post annealing. The CoPt and the FePt binary alloys
were completely mixed and had a L1(o)-type ordered structure, as confirmed
by single (222) peaks and by the linear variation of the lattice constant a
lpha(o). The ordered structure of the FePt alloy was thought to have formed
from the disordered structure by an inhomogeneous process, which was confi
rmed by the asymmetric peak shapes. The lattice parameter alpha(o) varied l
inearly with the Fe content while the coercivity showed a minimum value at
the equiatomic composition of the Fe and the Co atoms.