We report magnetic and transport properties of La 1Ϫx Ba x MnO 3 (xϭ0.05-0.33) epitaxial thin films. Compared with the corresponding bulk materials, the ferromagnetic transition temperature is reduced in the compressive strained La 1Ϫx Ba x MnO 3 thin films with xϭ0.3 and 0.33, but enhanced significantly in the tensile strained thin films with xр0.2. Especially, ferromagnetism and low field colossal magnetoresistance effect were observed around room temperature in xϭ0.1 thin film, and as xϭ0.05, a spin-canting insulating state in bulk shifts to ferromagnetic metallic state in thin film. The phase diagram of La 1Ϫx Ba x MnO 3 thin films was obtained, and strain effect on these novel properties was discussed.

A transparent ZnO homostructural light-emitting diode (LED) with a structure of Au electrode/p(i)-ZnO film/n-ZnO single crystal/In electrode was fabricated using the technique of N2O plasma-enhanced pulsed laser reactive deposition. The contact between the p(i)-ZnO layer and n-ZnO wafer was found to exhibit nonlinear and rectifying current–voltage (I–V) characteristics. A current injection emission with bluish-white light was clearly observed at room temperature, and its intensity increased with increases in the injected electric current.

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Using pulsed-laser deposition, ferroelectric Bi4Ti3O12 (BiT) films were grown on Si(100) with and without an ultrathin buffer layer of silicon oxynitride (SiON), and the interface states were investigated using X-ray photoelectron spectroscopy. For both as-grown specimens, the additional oxidation of the interface Si was observed, and their thicknesses were almost identical. Due to the postannealing at 700°C in an oxygen ambient, on the other hand, a large difference in the Si oxidation was observed between the two specimens. The BiT films on Si(100) without the SiON buffer layer failed in preventing the significant development of the interfacial Si oxidation. On the contrary, it was clarified that the 1.3-nm-thick SiON buffer layers suppressed the additional oxidation to less than 3.5 nm.

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