COMPENSATION DOPING OF BA0.7SR0.3TIO3 THIN-FILMS

We have investigated the effects of Mn impurities on Ba0.7Sr0.3TiO3 th in films using x-ray photoemission spectroscopy. Mn acts as an electro n acceptor, compensating for the charge density found in nominally und oped films. This causes a greatly increased depletion width in accepto r-doped films. We also present evidence that acceptor-doped films have an increased barrier to thermionic emission of electrons from Pt cont acts into the dielectric. This may explain the decrease in leakage cur rent observed in some acceptor-doped titanates. (C) 1998 American Inst itute of Physics. [S0003-6951(98)00139-9].