Bipolar Resistive Switching in Epitaxial Mn3O4 Thin Films on Nb-Doped SrTiO3 Substrates**Supported by the National Basic Research Program of China under Grant Nos 2011CB921904 and 2012CB927402, the National Natural Science Foundation of China under Grant Nos 11074142 and 11021464, the Key Project of the Ministry of Education of China under Grant No 309003.

Abstract

Spinel (001)-orientated Mn3O4 thin films on Nb-doped SrTiO3 (001) substrates are fabricated via the pulsed laser deposition method. X-ray diffraction and high-resolution transmission electron microscopy indicate that the as-prepared epitaxial film is well crystallized. In the film plane the orientation relationship between the film and the substrate is [100]Mn3O4‖[110] Nb-doped SrTiO3. After an electroforming process, the film shows bipolar nonvolatile resistance switching behavior. The positive voltage bias drives the sample into a low resistance state, while the negative voltage switches it back to a high resistance state. The switching polarity is different from the previous studies. The complex impedance measurement suggests that the resistance switching behavior is of filament type. Due to the performance reproducibility and state stability, Mn3O4 might be a promising candidate for the resistive random access memory devices.