COMPUTER-SIMULATION STUDIES OF STRONTIUM-TITANATE

We present the results of computer simulation studies of SrTiO3. After deriving a reliable potential model, me concentrate on the properties of defects and dopants. Our calculations are used to propose a defect model that is consistent with experimental observations. For vacancy disorder, the calculations show that SrTiO, (Schottky) and SrO (Schott ky-like) disorder have very similar energy, with a small tendency for the development of Sr deficiency at higher temperatures. All mono- and divalent cations prefer to substitute at strontium sites. For trivale nt cations, three types of mechanism (Sr and Ti substitution and self- compensation) are proposed, whereas for tetravalent cations substituti on on both A and B sites may occur, depending on the ionic radius.