Capacitance of (001)SrRuO3/(001)SrTiO3 and (110)SrRuO3/(110)SrTiO3 interfaces in epitaxial heterostructures grown on LaAlO3 substrates

The temperature dependence of the permittivity ? measured at T = 120?300 K for SrTiO₃ layers in SrRuO₃/SrTiO₃/SrRuO₃ heterostructures grown on (001)-and (110)-oriented LaAlO₃ substrates is well approximated by the relation ?₀/? = C ₀ ^?1 (T ? T _CW) + ?₀/?_I, where the C ₀ and T _CW values virtually coincide with the Curie constant and the Curie-Weiss temperature, respectively, for SrTiO₃ single crystals. The specific capacitance of the (001)SrRuO₃/(001)SrTiO₃ and (110)SrRuO₃/(110)SrTiO₃ interfaces calculated using the obtained ?_I values is 2.7 and 6.4 μF/cm², respectively.