Bi3.15Nd0.85Ti3O12 (BNdT) thin films were deposited on Pt/Ti/SiO2/Si substrates using a sol-gel process. The film annealed at 750℃ is composed of grains of 50-100nm in diameter. The fine grains show nearly random orientations. "Micropores" were frequently observed at the junctions of the grains and they are mostly amorphous, while sometimes containing very fine crystalline particles with sizes of only a few nanometers. The BNdT film capacitors with a Pttop electrode showed excellent ferroelectric properties. The remanent polarization and the coercive field were in the range of 41-43 mC/cm2 and 70-84kV/cm, respectively. The BNdT capacitors did not show any significant fatigue up to 53109 switching cycles at a frequency of 1MHz.

Epitaxial La0.7Ca0.3MnO3 (LCMO) thin films of a thickness ～170nm were grown on (001) LaAlO3 (LAO) and (001) SrTiO3 (STO) substrates by pulsed laser deposition. Transmission electron microscopy and associated techniques have been applied to investigate the microstructures introduced by lattice mismatch that are responsible for the observed differences in properties between these two films. Numerous secondary phase rods were observed in both films. For the LCMO/LAO film, Ca-deficient secondary-phase rods originated in the film after a thickness of about 25nm and were found to be responsible for relieving in-plane compressive stress during the island growth. In the case of STO substrate, however, almost all of secondary-phase rods initiated at the film-substrate interface. The lattice mismatch between LCMO and STO is relaxed into regions of good coherent fit separated by such secondary phases, possibly resulting from interfacial reaction. The two types of substrates lead to the formation of two different crystallographic domain structures in the LCMO films. The film on LAO exhibits an almost pure [110] out-of-plane texture with 90° domains in plane. In contrast, the film grown on STO consists of mixed domains of [001] and [110] orientations and is dominated by [001] texture.

The surface states of sol-gel derived PbTiO3 thin films on Si substrates before and after Ar1 sputtering were studied by x-ray photoelectron spectroscopy (XPS). The results showed that there was no residual carbon or other impurity element in the films except some carbon surface contamination due to specimen handling or pumping oil. A large amount of absorbed oxygen was near the surfaces of the films. The chemical composition of the films was found to be stoichiometric, as proved by inductively coupled plasma results. The valence states of the ions indicated that the films were PbTiO3 with perovskite structure. The XPS spectra of the films after Ar1 sputtering for 10min differed greatly from those of as-prepared films. This probably results from the preferred sputtering of lead atoms and the production of many new dangling bonds during Ar1 bombardment.

The defect structure of a 350-nm-thick epitaxial Ba0.3Sr0.7TiO3 (BSTO) film grown on (001) LaAlO3 has been investigated using conventional and high-resolution transmission electron microscopy. The dominant defects in the film are edge-type threading dislocations (TDs) with Burgers vectors b5〈100〉and 〈110〉. Pure-screw TDs and partial TDs of mixed character were also observed. A rapid reduction of defect density occurred after the growth of the first 100nm BSTO adjacent to the interface. In the top layer of the film, all TDs with b5〈100〉are perfect while those with b5〈110〉are usually dissociated into two partials with a small separation (a few nanometers). However, in the near-interface layer of the film, many TDs with b5〈100〉are split into two or three partials. A high density of extended stacking faults with displacement vectors of 1 2〈110〉type were observed. The stacking faults are associated with dissociated dislocations and partial half loops. The mechanisms for the generation, dissociation and evolution of the TDs are discussed.

A type of dissociated misfit dislocation in epitaxial Ba0.3Sr0.7TiO3 thin films on (001) LaAlO3 substrates has been studied by high-resolution transmission electron microscopy. The dislocation has a Burgers vector [210] and is dissociated into four partial dislocations with Burgers vectors of type 1 2k110l. All partials can relieve the localized misfit strain and they are interacted with three 1 2k110l stacking faults lying on (001). The partials were generated during island nucleation and mosaic growth of the BSTO film, while a small amount of excess TiO2 during film deposition favored the formation of the 1 2k110l stacking faults.