Effects of cobalt substitution in L 10 -(Fe,Co)Pt thin films

We have studied the effect of cobalt substitution in L 1₀-Fe_{1 -x}Co_xPt films by means of x-ray magnetic circular dichroism (XMCD) and first-principles calculations. The magnetic moments of Fe (∼2.5 μ_B ) and Co (∼1.5 μ_B ) deduced using XMCD were almost unchanged upon Co doping, and the net magnetization decreases with increasing Co content. Calculation also showed that the 3 d electrons that have been added by Co substitution occupy only spin-down bands.