Photoemission study of (PbEuGd)Te layers under Gd or Te atoms treatment

Substitution of Gd3+ for Eu2+ ions in EuTe leads to the introduction of Gd 5d electrons to the conduction band and antiferromagnetic order of EuTe (Heisenberg magnetic semiconductor) can be replaced by ferromagnetic state due to RKKY interaction. The layers were grown by MBE method on BaF2 (1 1 1) substrate. Layer of Te deposited on top of (EuGd)Te protects surface of oxidation. Heating in 320 oC leads to Te atoms desorption and to improvement of the layer electronic structure. Additional Gd atoms were sequentially deposited on the layer of (PbGd)Te and set of Fano resonance curves were observed for ions of Gd. The Fano type photoemission resonance corresponding to the 4d-4f transitions were studied for Eu and Gd