Fabrication, microstructure and UPS spectra of Co: BaTiO3/Si(100) nano-composite films

Co: BaTiO3 nano-composite films were successfully fabricated by pulsed laser deposition on single crystal Si(100) surface. The micro-structure of the Co: BaTiO3 nano-composite films with about 30 nm and 100 nm thicknesses were studied by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The Co: BaTiO3 nano-composition films with the above thicknesses were unidirectionally prefer-oriented and polycrystalline, respectively. The atomic force microscopic (AFM) analysis indicated that there were tetragonal crystal grains in the films of about 30 nm thickness. The valence band of the films were investigated by ultraviolet photoelectron spectroscopy (UPS) in detail. The UPS spectra showed that density of electronic states (DOS) of the films with high concentration of Co grains were obviously different from that of bulk BaTiO3 single crystal.