Transport mechanism through metal-cobaltite interfaces

The resistive switching (RS) properties as a function of temperature were studied for Ag/La1−xSrxCoO3 (LSCO) interfaces. The LSCO is a fully relaxed 100 nm film grown by metal organic deposition on a LaAlO3 substrate. Both low and a high resistance states were set at room temperature, and the temperature dependence of their current-voltage (IV) characteristics was measured taking care to avoid a significant change of the resistance state. The obtained non-trivial IV curves of each state were well reproduced by a circuit model which includes a Poole-Frenkel element and two ohmic resistances. A microscopic description of the changes produced by the RS is given, which enables to envision a picture of the interface as an area where conductive and insulating phases are mixed, producing Maxwell-Wagner contributions to the dielectric properties.