STRUCTURE AND MICROSTRUCTURE OF LA1-XCAXMNO3-DELTA THIN-FILMS PREPARED BY PULSED-LASER DEPOSITION

La1-xCaxMnO3-delta(LCMO) thin films are grown by pulsed laser depositi on on a (100) SrTiO3 substrate at temperatures between 530 and 890 deg rees C. The magnetotransport properties show a high negative magnetore sistance and a shift of the maximum of the R(T) curve as a function of temperature. The Curie temperature changes with deposition temperatur e and film quality in the range of 100-220 K. The film quality is char acterized by x-ray diffraction and transmission electron microscopy (T EM); film and target compositions were verified by atomic emission spe ctroscopy. The local structure of the film depends on the growth condi tions and substrate temperature. TEM reveals a slight distortion of th e film possibly leading to a breakdown of the symmetry from orthorhomb ic to monoclinic. At the highest growth temperatures, a well-defined i nterface is observed within the LCMO film, parallel to the substrate s urface; this interface divides the film into two lamellae with a diffe rent microstructure. The one close to the substrate is perfectly coher ent with the substrate, suggesting that it is strained as a result of the lattice parameter mismatch; the upper lamella shows a typical doma in structure with unusual translation interfaces characterized by a di splacement vector of the type 1/2[101](o) and 1/2[101](0) when referre d to the orthorhombic lattice. [S0163-1829(98)01836-0].