Au and Fe magnetic moments in disordered Au-Fe alloys

We report on the magnetic moments of Au and Fe in fcc and bcc disordered Au-Fe alloys determined via a combination of x-ray magnetic circular dichroic measurements at the L-3,L-2 edges of Au and superconducting quantum interference device magnetometry. The 5d induced magnetic moment of Au in the fcc alloys scales with the number N of nearest Fe neighbors, from M-Au=0.1 mu(B)/atom for N=3 to M-Au=0.2 mu(B)/atom for N=6. Fe in these alloys is in a high-spin state, which carries a total magnetic moment of about 3 mu(B)/atom. The maximum value of 5d induced magnetic moment of Au is 0.33 mu(B)/atom and is exhibited when Au is placed as an impurity in a bcc Fe environment. The ratio of the orbital-to-spin 5d magnetic moment of Au is M-L/M-S approximate to 0.2 in all samples. The experimental results are discussed with respect to first principles calculations.