Local moment of Ir in Fe, Co and Ni hosts probed by Ir L-2,L-3 edge X-ray magnetic circular dichroism

The formation of an induced 5d magnetic moment on Ir in Fe97Ir3,Co95Ir5 and Ni95Ir5 alloys has been investigated by X-ray magnetic circular dichroism (XMCD) and X-ray absorption spectra (XAS) measurements at Ir L-2,L-3 edges. Using a sum rule which relates the integrals of these spectra with the ground state expectation value of the orbital angular momentum [L-Z] of the probed atom, the orbital moment m(orb) of Ir could be determined as -0.071(2) mu(B) in an Fe host, -0.067(2) mu(B) in a Co host and -0.041(1) mu(B) in a Ni host. The spin magnetic moment m(spin) of Ir is also found to be the maximal in Fe and the minimal in Ni. The total moment of Ir is found to be approximately 1/5 of total moment of Fe, 2/13 of the total moment of Co, and 1/4 of the total moment of Ni.