title: Nanoscale Electronic Inhomogeneity in In2Se3 Nanoribbons Revealed by Microwave Impedance Microscopy.
abstract: Driven by interactions due to the charge, spin, orbital, and lattice degrees of freedom, nanoscale inhomogeneity has emerged as a new theme for materials with novel properties near multiphase boundaries. As vividly demonstrated in complex metal oxides (see refs 1-5) and chalcogenides (see refs 6 and 7), these microscopic phases are of great scientific and technological importance for research in high-temperature superconductors (see refs 1 and 2), colossal magnetoresistance effect (see ref 4), phase-change memories (see refs 5 and 6), and domain switching operations (see refs 7-9). Direct imaging on dielectric properties of these local phases, however, presents a big challenge for existing scanning probe techniques. Here, we report the observation of electronic inhomogeneity in indium selenide (In(2)Se(3)) nanoribbons (see ref 10) by near-field scanning microwave impedance microscopy (see refs 11-13). Multiple phases with local resistivity spanning 6 orders of magnitude are identified as the coexistence of superlattice, simple hexagonal lattice and amorphous structures with approximately 100 nm inhomogeneous length scale, consistent with high-resolution transmission electron microscope studies. The atomic-force-microscope-compatible microwave probe is able to perform a quantitative subsurface electrical study in a noninvasive manner. Finally, the phase change memory function in In(2)Se(3) nanoribbon devices can be locally recorded with big signals of opposite signs.
authors.affiliation: Department of Applied Physics and Department of Materials Science and Engineering, Stanford University, Stanford, California 94305.
authors.forename: Keji
authors.initials: K
authors.lastname: Lai
authors.forename: Hailin
authors.initials: H
authors.lastname: Peng
authors.forename: Worasom
authors.initials: W
authors.lastname: Kundhikanjana
authors.forename: David T
authors.initials: DT
authors.lastname: Schoen
authors.forename: Chong
authors.initials: C
authors.lastname: Xie
authors.forename: Stefan
authors.initials: S
authors.lastname: Meister
authors.forename: Yi
authors.initials: Y
authors.lastname: Cui
authors.forename: Michael A
authors.initials: MA
authors.lastname: Kelly
authors.forename: Zhi-Xun
authors.initials: ZX
authors.lastname: Shen