Fano Resonance of Eu2+and Eu3+in (Eu,Gd)Te MBE Layers

Resonant photoemission spectroscopy, with application of synchrotron radiation, was used to study the valence band electronic structure of clean surface of (EuGd)Te layers.Fano-type resonant photoemission spectra corresponding to the Eu 4d-4f transition were measured to determine the contribution of 4f electrons of Eu 2+ and Eu 3+ ions to the valence band.The resonant and antiresonant photon energies of Eu 2+ ions were found as equal to 141 eV and 132 eV, respectively and for Eu 3+ ions were found as equal to 146 eV and 132 eV, respectively.Contribution of Eu 2+ 4f electrons was found at the valence band edge while for Eu 3+ it was located in the region between 3.5 eV and 8.5 eV below the valence band edge.