Dielectric properties of SrTiO/sub 3/ thin films at low temperature

The authors have fabricated YBCO (or Ag)/SrTiO/sub 3//YBCO capacitors for low-frequency measurements and SrTiO/sub 3//YBCO/LaAlO/sub 3/ coplanar-waveguide end-coupled resonators for high-frequency measurements of the SrTiO/sub 3/ dielectric constant at low temperatures. From the capacitor measurements, values for the dielectric constant ranging from approximately 200 to 800 were obtained for films of various thicknesses. This behavior of the thin-film dielectric constant was found to differ from that of the bulk crystal. >