Realization of the three-dimensionally architected nanostructures for the strongly electron correlated metal oxides and investigation of their nanoscale metal-insulator transition properties

Abstract

Functional metal oxides with strongly correlated electron system, such as vanadium dioxide, manganite, and so on show first-order metal-insulator phase transition (MIT) with a change in conductivity by several orders magnitude. Since the novel properties of the metal oxides are dominated by competing nanoscale and/or microscale electronic phases, to understand exotic nanoscale electronic domain properties and utilize their superior properties as device functionalities, the three-dimensional (3D) nano-structuring is one of the most effective approaches. In this paper, I show our original nanofabrication technique, which realizes the construction of the well-defined 3D metal oxide nanostructures in atomic resolution. The nano-confinement of the electronic domains can allow direct investigation of its MIT properties. We revealed that a single electronic nanodomain exhibited an intrinsic first-order MIT and their transition points were distributed. These results are the first demonstration approaching the transition dynamics, which can be a good guideline for realizing the functional nanoelectronic devices based on the functional metal oxides.