Anatomy of vertical heteroepitaxial interfaces reveals the memristive mechanism in Nb₂O₅-NaNbO₃ thin films

Dynamic oxygen vacancies play a significant role in memristive switching materials and memristors can be realized via well controlled doping. Based on this idea we deposite Nb₂O₅-NaNbO₃ nanocomposite thin films on SrRuO₃-buffered LaAlO₃ substrates. Through the spontaneous phase separation and self-assembly growth, two phases form clear vertical heteroepitaxial nanostructures. The interfaces between niobium oxide and sodium niobate full of ion vacancies form the conductive channels. Alternative I-V behavior attributed to dynamic ion migration reveals the memristive switching mechanism under the external bias. We believe that this phenomenon has a great potential in future device applications.