Local conduction in junctions composed of Pt and single-crystalline Nb-doped SrTiO3

We have investigated the electrical properties of junctions composed of Pt and Nb-doped SrTiO3 single crystals. The fabricated junction shows rectifying and hysteric current-voltage characteristics with high and low resistance states. The current is less dependent on the top electrode area regardless of the resistance state, while the junction capacitance exhibits a linear relationship with the area in both resistance states. The current also shows temporal changes depending on a polarity of applied voltages. The observed behaviors can be understood by considering an existence of conducting channels, along which the current flows dominantly through the capturing and releasing processes of electrons. (C) 2009 Elsevier B.V. All rights reserved.