Capacitance of the La0.67Sr0.33MnO3/(Ba,Sr)TiO3 interface induced by electric field penetration into the manganite electrode

(001)La0.67Sr0.33MnO3/(001)(BaxSr1 − xTiO3/(001)La0.67Sr0.33MnO3(x= 0–0.25) three-layer heterostructures are grown by laser evaporation on (001)La0.3Sr0.7Al0.65Ta0.35O3 single-crystalline substrates. In a wide temperature range (≈150 K), effective permittivity ɛ of (1000 nm)Ba0.25Sr0.75TiO3 and (1000 nm)SrTiO3 films grown obeys the relationship ɛ ∼ (T − TCW)−1, where TCW is the Curie-Weiss temperature for related bulk crystals. Using experimental dependences ɛ(T), the capacitance of the (001)La0.67Sr0.33MnO3/(001)BaxSr1−xTiO3 and (001)La0.67Sr0.33MnO3/(001)SrTiO3 interfaces, which is due to electric field penetration into the manganite electrode, is estimated (Cint≈4μF/cm2). At bias voltages of ± 2.5 V, the change in the permittivity of the STO and BSTO films in the heterostructures studied reaches 25 and 45%, respectively.