Dielectric Parameters of Elastically Strained Heteroepitaxial SrTiO3 Films

Abstract

Three-layer epitaxial SrRuO₃/SrTiO₃/SrRuO₃ heterostructures with the 900-nm-thick intermediate layer of strontium titanate have been grown on single-crystal (001)La_0.29Sr_0.71Al_0.65Ta_0.35O₃ substrates by the laser evaporation method. Plane-parallel film capacitors have been formed on the basis of the grown heterostructures using photolithography and ion etching. Temperature dependences of the dissipation factor have been measured for these capacitors at different bias voltages applied to strontium ruthenate electrodes. Temperature dependences of the permittivity of the intermediate SrTiO₃ layer in the formed capacitor structures are visualized with compensation of the internal electric field and without it. The reasons for the sharp increase in the dielectric loss in the formed film capacitors at temperatures below 50 K are analyzed.