Optical Constants of Ferromagnetic Iron via2pResonant Magnetic Scattering

We have determined the optical constants at the $2p$ edges of iron by measuring the Bragg scattering from a Fe/V superlattice using elliptically polarized photons whose energies were tuned across the Fe $2p$ resonances (700–730 eV). The analysis of the Bragg peak displacement as a function of photon energy and sample magnetization, together with standard absorption measurements, allowed to determine the complete dielectric tensor for Fe, including its off-diagonal terms.