FERROELECTRIC PHASE-TRANSITION IN BATIO3 FILMS

Epitaxial BaTiO3 single crystals were grown on Pt/MgO (Pt for electrodes, MgO For substrates) by means of the activated reactive evaporation technique, X-ray diffraction patterns were measured to clarify the properties such as the temperature dependence of lattice parameters. It was found that the temperature dependence of lattice parameters and integrated intensities of Bragg reflections showed different behavior depending on the film thickness. The relative dielectric constant epsilon(r) was measured in order to investigate the dielectric properties of the films. Film crystals of BaTiO3 showed the phase transitions which are different from those in hulk state.