Impact of the electrical forming process on the resistance switching behaviors in lanthanum-doped strontium titanate ceramic chip devices

The resistance switching (RS) behaviors of La-doped SrTiO3 ceramics before and after the electrical forming process (E-forming) have been investigated in order to clarify the RS mechanism. The formation processes for the double Schottky barriers (DSBs), such as reoxidation and E-forming, are important to realize stable RS properties, and Joule heating strongly influences the RS behaviors after the E-forming. Thermally stimulated current measurements clearly indicated the contribution of defects related to oxygen vacancies to the current conduction through DSBs and RS phenomena both before and after the E-forming. Experimental results suggest that the electron trapping in the defects and/or the defect migration induced by the voltage application and Joule heating change the space-charge distribution near the grain boundaries, resulting in the change in the resistance state.