\textbf{\textit{In Situ}}\textbf{ Resistivity of Endotaxial FeSi}$_{\mathrm{\mathbf{2}}}$\textbf{ Nanowires on Si(110)}

ORAL

Abstract

We present \textit{in situ} Ultra-High Vacuum (UHV) measurements of the resistivity $\rho $ of self-assembled endotaxial FeSi$_{\mathrm{2}}$ nanowires (NWs) on Si(110) using a variable-spacing two-point method with a moveable Scanning Tunneling Microscope (STM) tip and fixed contact pad. The resistivity at room temperature was found to be nearly constant down to NW width W $=$ 4 nm, but rose sharply to nearly double the bulk value at W $=$ 3nm. These data are not well-fit by a simple Fuch-Sondheimer model for boundary scattering, suggesting that other factors, possibly quantum effects, may be significant at the smallest dimensions. For a NW width of 4 nm, partial oxidation increased $\rho $ by approximately 50{\%}, while cooling from 300K to 150K decreased $\rho $ by approximately 10{\%}. The relative insensitivity of $\rho $ to NW size or oxidation or cooling is attributed to a high concentration of vacancies in the FeSi$_{\mathrm{2}}$ structure, with a correspondingly short length for inelastic electron scattering, which obscures boundary scattering except in the smallest NWs. It is remarkable that the vacancy concentration persists in very small structures.

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Authors

  • Peter Bennett

    Arizona State University

  • Scott D. Bergesen

    Santa Fe Institute, Arizona State University, Department of Physics and Center for Biological Physics, Arizona State University, Brigham Young University Department of Physics and Astronomy, Brigham Young University, Utah Valley University, Dixie State College, Advisor, Student, Massachusetts Institute of Technology, Thomas Jefferson National Accelerator Laboratory, Colorado College, United States Air Force Academy, Georgia Institute of Technology, Utah State University, Brigham Young University - Idaho, Utah State University- Logan, National Institute of Standards and Technology, Humboldt State University, UC Santa Cruz, Institut de Chimie des Substances Naturelles, Arizona State Univ, University of Colorado at Colorado Springs, National Jewish Health, Department of Physics, The University of Texas at Austin, Department of Physics, New Mexico State University, U. S. Air Force Academy, Brigham Young Univ - Provo, University of New South Wales, University of Texas, University of Warwick, University of Louisiana, Department of Physics and Astronomy, Brigham Young University, Provo, Utah 84602, USA., Center for Materials Genomics, Department of Mechanical Engineering and Materials Science and Department of Physics, Duke University, Durham, North Ca, Duke University, Durham, North Carolina., Brigham Young University -- Provo, Utah, General Atomics -- San Diego, California, Department of Mathematics, University of British Columbia, Department of Physics, Arizona State University, UC Riverside, UMASS, STScI, NOAO, UT Austin, Texas A&M, Arizona State Univeristy, New Mexico State Univ, Los Alamos National Laboratory, Colorado State Univ, Department of Physics, Oregon State University, Colorado School of Mines, University of Alaska, Fairbanks, The Peac Institute of Multiscale Modeling, UNSW Canberra