Large Room-Temperature Resistive Switching Behavior in Spinel Structured Nanoparticle Compacts.

Here we report an abrupt and large bipolar switching behavior in the form of nanoparticle assembly consisting of an infinite number of monodispersed magnetic oxide single-crystallines. In the assembly of magnetite nanoparticles with size below 10 nm, we observed a room temperature current-voltage hysteresis with an abrupt and large bipolar resistive switching (switching ratio of $\sim $ 2000 {\%}). We also found that such switching behaviors can be general phenomena for nanoparticle assemblies: not limited to magnetites but also consistently observed for other kinds of spinel structured nanoparticles with different compositions. Such a huge switching phenomenon it has never been observed before in bulk powders, particularly at room temperature. Our results showed clearly that the new I-V hysteresis is dependent on the nanoparticle size, and arises from interparticle contacts. In an effort to understand and interpret the origin of the bipolar reversible switching behavior, a new theoretical model was suggested in this work.