Interfacial capacitance in epitaxial heterostructures La0.67Ca0.33MnO3/SrTiO3/La0.67Ca0.33MnO

Epitaxial trilayer heterostructures of the type La0.67Ca0.33MnO3 /SrTiO3 /La0.67Ca0.33MnO3 were grown by laser ablation on (001)[(LaAlO3)(0.3) + (Sr2AlTaO6)(0.7)] substrates. The real part of the dielectric permittivity epsilon and the loss factor tan delta of a 1100-nm-thick SrTiO3 interlayer were studied in the temperature interval T = 4.2-300 K in a nonbiased state and at a bias voltage of +/-2.5 V applied to the manganite electrodes. Using the temperature dependence epsilon(T) measured for the SrTiO3 layer grown between the manganite electrodes, we have estimated the capacitance of La0.67Ca0.33MnO3 /SrTiO3 interfaces (C-1 approximate to 2 muF/cm(2)) related to the electric field penetrating from the interlayer into La0.67Ca0.33MnO3 . (C) 2004 MAIK "Nauka/Interperiodica".