Resonant photoemission studies of Gd/PbGdTe

The paper presents the experimental results of the electronic band structure study of the clean PbGdTe surface and this surface additionally doped with gadolinium atoms. Gadolinium thin films (0.4 and 1 nm) were grown epitaxially on the PbGdTe substrate. After the second evaporation the sample was annealed. Heating of the sample covered by metal atoms led to the diffusion of the gadolinium atoms into the surface layer of the sample. After each stage of the sample treatment (surface cleaning, Gd evaporation and annealing) resonant photoemission spectra were acquired for the photon energy range of 130-152 eV, corresponding to the Fano-type Gd 4d-4f resonance. The emission from the Gd 4f shell of the atoms built into the surface layer of PbGdTe was revealed and its binding energy was determined as equal to 10.4 eV