Perovskite Thin Films

The unique combination of (a) highly brilliant x-rays§produced in a modern third generation synchrotron§source, (b) the availability of a fast,§single-photon counting area pixel detector and (c) a§pulsed laser deposition equipment for in-situ growth§enables one to study both the structure and kinetics§of the thin film growth of perovskites. The surface§structure of titanium-dioxide-terminated strontium§titanate (STO) was analyzed by surface x-ray§diffraction (SXRD) for two different environments:§One (cold) at room temperature and in ultra-high§vacuum, and the other (hot) at elevated temperatures§and in an oxygen background, i.e., under conditions§typical for perovskite thin film growth. SXRD was§used to determine the atomic structures of lanthanum§strontium manganate thin films, grown§monolayer-by-monolayer on STO by pulsed laser§deposition. Structures were solved using the COBRA§phase-retrieval method and subsequent structural§refinement. These results allowed concluding on the§onset of colossal magnetoresistance. In-situ kinetic§studies of the thin film growth led to the§proposition of a novel energetic smoothing mechanism§for the growth of complex metal-oxide thin films.