Optical properties of thin epitaxial Ba0.8Sr0.2TiO3 films

Abstract

The properties of nanodimensional (Ba 0.8 , Sr 0.2 )TiO 3 films on single crystal magnesia substrates are studied. The films are applied by rf sputtering and grow in the layer by layer mode. The lattice parameters are measured by the X ray diffraction method. The transmission of the films with different thicknesses is stud ied in the wavelength range 190-1100 nm. When analyzing experimental optical parameters, additional relaxation parameters depicting a final lifetime of the oscillator are used to characterize the refractive index and absorption factor in the dispersion relation. Such an approach allows a more accurate approximation of experimental data.

Thickness dependence of the properties of epitaxial barium strontium titanate thin films

“…For MgO, this energy is 7.9 eV [25]. For BST films, this energy is within 3.9-5.1 eV [26], i.e., the difference in the potential box depth is of the order of 3-4 eV. Due to tunneling, electrons will "flow" to the deeper poten tial well until band edges become leveled at the appeared electrostatic energy.…”