Temperature Dependence of Dielectric Absorption Current of SrTiO3 Thin-Film Capacitor

Temperature dependence of dielectric absorption current of the Pt/SrTiO3/Au capacitor was investigated. The time dependence of the dielectric absorption currents obtained from I-t measurements for the time window between 1 and 50 s can be fitted by a superposition of three Debye-type relaxations. Relaxation time constant and capacitance which characterize each relaxation species show different temperature dependences. Relaxation time constants are independent of temperature. On the other hand, relaxation capacitances obey Arrhenius' equation with the same activation energy of 0.18 eV. This low activation energy suggests that the observed dielectric absorption current is electronic. Possible mechanisms for the observed dielectric relaxation are discussed based on these results.