Niobium implantation effects in BaTiO3 and SrTiO3

Abstract Single crystals of BaTiO3 and SrTiO3 have been implanted at room temperature with 150 keV Nb+ ions to doses ranging from 1014 to 1017 ions cm2. The structure and the oxidation state of the damaged layer have been investigated by Rutherford backscattering-ion channeling and electron spectroscopy, respectively. SrTiO3 is rendered amorphous at relatively low doses of 2 × 1015 ions cm−2, but the damage is efficiently annealed at 450°C for 1 2 h. For both materials, the oxidation state of niobium varies from + 5 to + 2 along the depth. Moreover, a considerable chemical shift (2.3 eV) is observed for barium in BaTiO3.