Thermal evolution and diffusion of Eu-implanted SrTiO3

Abstract

Europium ions of 70 keV energy were implanted at room temperature in SrTiO3 single crystals with a fluence of 5 × 1016 ions cm−2. The damage and the site locations of cations in the implanted layer were investigated by Rutherford backscattering spectrometry in channeling geometry. The oxidation states of the involved atomic species along the Eu distribution profile were determined by X-ray photoemission spectroscopy (XPS). Following the implantation a fully amorphized layer of about 60 nm is generated and XPS spectra reveal europium in Eu2+ and Eu3+ states. Thermal treatments performed in air at 1050 °C for durations up to 12 h have efficently induced both recrystallization of the host lattice and europium diffusion. The XPS results indicate that this diffusion phenomenon can be correlated to a given oxidation state, namely Eu2+.