Magneto-Optical Scattering from Nanometer-Scale Particles

ORAL

Abstract

We present calculations of the magneto-optical properties of magnetic particles with nanometer-scale dimensions. The scattering is calculated with the discrete dipole approximation (DDA). The DDA is a finite element approximation in which the particle is divided into a regular grid of radiating dipoles with grid spacing much smaller than the wavelength of incident radiation. The implementation of this approximation for gyrotropic (magneto-optical) media is discussed as well as the interpretation of the calculated scattering matrix. Calculations are performed for spherical particles, wires and collections of interacting particles. We also present experimental Faraday rotation spectra of magnetite nanoparticles in a polymer matrix. The data show a red shift of particular spectral features as a function of particle concentration. This is shown to be qualitatively consistent with model calculations which include interparticle interactions.

–

Authors

  • Kevin Stokes

    Advanced Materials Research Institute, University of New Orleans, New Orleans, LA

  • R.F. Kelly

    SVT Associates, Department of Material Science and Engineering, Department of Chemistry, University of Florida, Florida International University, WebAssign, North Carolina State University, Broughton High School, Dept.~of Chemistry, Univ.~of Florida, Dept.~of Physics, Univ.~of Florida, National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32306, USA, Center for Superconductivity Research, Dept. of Physics, University of Maryland, College Park, MD, 20742, USA, Dept. of Physics, University of Florida, 32611, USA, Experimentalphysik VI, Center for Electronic Correlations and Magnetism, Institute of Physics, Augsburg, Germany, Physics \& Astronomy, UNC-CH, Chapel Hill, NC, University of North Carolina, Auburn University, University of Virginia, Tech. Univ. Eindhoven, University of Florida, Los Alamos National Labs, University of New Mexico, Advanced Materials Research Institute, University of New Orleans, New Orleans, LA, Department of Physics, University of Florida, UF, NHMFL, FSU / NHMFL, FSU, University of Arkansas, Dept. of Physics and Astronomy, University of Delaware, Newark, DE 19716, USA, Dept. of Physics, University of Florida, Gainesville, FL 32611-8440, USA, Dept. Chemistry Florida State Univeristy, University of Brewen, Tohoku University, Okayama University, Dept of Chemistry, Florida State University, Dept. of Chemistry, Florida State University, National High Magnetic Field Laboratory, Tallahassee, FL, Laboratoire Lois Neel, Grenoble, France, Dept. of Chemistry, Texas A\&M University, Tsinghua Univ., INEL, JINR, Vanderbilt Univ./LBNL, Vanderbilt Univ., SVT Associates, Inc., Department of Chemical Engineering, University of Florida, Department of Materials Science and Engineering, University of Florida, Department of Electrical Engineering, National Central University, Taiwan, University of Miami, North Carolina Central University, University of Missouri Rolla, AB Millimetre, France, Thomas Keating Ltd., UK, Dept. of Physics, Univ. of Florida, Department of Material Science and Engineering University of Florida, Department of Chemistry University of Florida, Department of Chemical Eng. University of Florida, Naval Research Lab, Washington, DC, University of Rajshahi, LENIN All Russian Electrotechnical Institute, Moscow, Russia, Independent Researcher, Argentina