The MBE Growth and Optical Quality of BaTiO3 and SrTiO3Thin Films on MgO

Abstract

AbstractHigh quality epitaxial BaTiO3 and SrTiO3 have been grown on MgO, stabilized at a one unit cell height, and grown to film thicknesses of 0.5 - 0.7 μm. These relatively thick films remain adherent when thermally cycled between growth temperatures and room temperature, are crack free with high optical quality, and have both in-plane and out-of-plane X-ray rocking curves of 0.3–0.5°. These films have been grown using molecular beam epitaxy (MBE) methods starting with the TiO2 layer of the perovskite structure. The TiO2-Iayer/MgO interface uniquely satisfies electrostatic requirements for perovskite heteroepitaxy and provides the template structure that leads to the high quality films that are obtained. Wavelength dependence of optical loss has been characterized between 475 nm and 705 nm with loss coefficients < 1dB/cm being obtained at the He-Ne wavelength.