Electrical-field-driven metal-insulator transition tuned with self-aligned atomic defectsElectronic supplementary information (ESI) available. See DOI: 10.1039/c5nr03251b

• Main Authors: Syrlybekov, Askar, Wu, Han-Chun, Mauit, Ozhet, Wu, Ye-Cun, Maguire, Pierce, Khalid, Abbas, Ó Coileáin, Cormac, Farrell, Leo, Heng, Cheng-Lin, Abid, Mohamed, Liu, Huajun, Yang, Li, Zhang, Hong-Zhou, Shvets, Igor V
• Format: Article
• Language: English
• ISSN: 2040-3364; 2040-3372
• DOI: 10.1039/c5nr03251b

Recently, significant attention has been paid to the resistance switching (RS) behaviour in Fe 3 O 4 and it was explained through the analogy of the electrically driven metal-insulator transition based on the quantum tunneling theory. Here, we propose a method to experimentally support this explanation and provide a way to tune the critical switching parameter by introducing self-aligned localized impurities through the growth of Fe 3 O 4 thin films on stepped SrTiO 3 substrates. Anisotropic behavior in the RS was observed, where a lower switching voltage in the range of 10 4 V cm −1 is required to switch Fe 3 O 4 from a high conducting state to a low conducting state when the electrical field is applied along the steps. The anisotropic RS behavior is attributed to a high density array of anti-phase boundaries (APBs) formed at the step edges and thus are aligned along the same direction in the film which act as a train of hotspot forming conduits for resonant tunneling. Our experimental studies open an interesting window to tune the electrical-field-driven metal-insulator transition in strongly correlated systems. An anisotropic resistance switching behavior has been observed in Fe 3 O 4 thin films on stepped SrTiO 3 substrates.