Optical properties and the temperature dependence of the permittivity of a multilayer structure of
a variozone ferroelectric barium-strontium titanate deposited on a single-crystal leucosapphire substrate are
studied. The results of mathematical modeling and experimental study of the transmission and reflection
coefficient of the structure in the spectral range of 300–1100 nm at small angles of light incidence on the surface as well as the temperature dependence of the permittivity in the temperature range 300–400 K are presented.