Magnetic linear dichroism in Gd 4f and 4d photoemission of magnetic interfaces

We present a combined experimental and theoretical study of magnetic linear dichroism in the angular distribution (MLDAD) of Gd 4f and 4d core level photoemission. Expressions are given for the spectral shape and photon energy dependence by using the method of fundamental spectra. The results are compared with experimental data for a thin Gd layer on Fe(100) and for a Fe/Gd/Fe interface. Compared to magnetic circular dichroism (MCD) in 4f photoemission, the MLDAD is much smaller and undergoes a sign change around 80 eV kinetic energy. We show that for 4f and 4d emission the spectral shapes of the MLDAD and MCD are in principle different, but in practice these differences are too small to observe.