Dielectric response of Ba0.05Sr0.95TiO3(110) films to variations in temperature and electric field

Artikel i vetenskaplig tidskrift, 2015

Three-layer epitaxial heterostructures, in which a 1000-nm-thick intermediate layer of Ba 0.05 Sr 0.95 TiO 3 is integrated with strontium ruthenate conducting electrodes, have been grown by laser evaporation. Using photolithography and ion etching, film parallel-plate capacitors SrRuO 3 /Ba 0.05 Sr 0.95 TiO 3 /SrRuO 3 are formed based on the grown heterostructures. A sharp maximum in the temperature dependence of the capacitor capacitance is observed at T ≈ 75 K. At T < 100 K, the capacitance decreases by 50–60% upon applying a bias voltage V b = ±2.5 V to the oxide electrodes. The estimate of the specific capacitance (~2.1 μF/cm2) of the Ba 0.05 Sr 0.95 TiO 3 (110)/SrRuO 3 (110) interface is obtained. For T > 250 K and the measuring signal frequency of 1 kHz, the dielectric loss tangent of the film capacitors increases exponentially with increasing temperature.