Bias polarity-dependent unipolar switching behavior in NiO/SrTiO3 stacked layer
Sun Xian-Wen, Jia Cai-Hong, Liu Xian-Sheng, Li Guo-Qiang, Zhang Wei-Feng
       

(color online) Schematic diagrams of the formation and movement of conduction paths composed of oxygen vacancies under (a) negative and (b) positive bias.