Leakage current characteristics of laser-ablated SrBi2Nb2O9 thin films

We have studied the leakage current conduction mechanism of pulsed-laser-deposited SrBi2Nb2O9 (SBN) thin films on platinized silicon substrates. The time-dependent dc leakage current densities of SBN thin films do not follow Curie-von Schweidler power law. Instead the contribution of conduction current is predominantly electronic. At lower fields, the leakage current follows the ohmic behavior, and it increases exponentially for higher fields. The leakage current density of the SBN thin films was studied at elevated temperatures, and the data were fitted with the Schottky emission model. The effective Richardson's constant was calculated to be about 8.7x10(-6) A/cm(2) K-2. The Schottky barrier height of the SBN thin films was estimated to be 1.37 eV. (C) 2002 American Institute of Physics.