Negative differential resistance and multilevel resistive switching in BaSrTiO3 films

Abstract

Epitaxial BaxSr1−xTiO3 (BST) films are grown on SrTiO3:Nb (NSTO) substrates by hydrothermal means. A Pt/BST/NSTO device exhibits typical rectification characteristics under relatively low voltage and forming-free bipolar resistive switching under relatively high voltage, with the resistance ratio between the high and low resistance states exceeding four orders of magnitude. Furthermore, negative differential resistance arises during the reset process, and multilevel resistive switching is achieved under various reset voltages. These behaviors in the Pt/BST/NSTO device are likely due to trapping/detrapping of electrons by oxygen vacancies at the Pt/BST interface.