Magnetodynamics of Multi-Scale Magnetic Dots in the Vortex State

POSTER

Abstract

A definite exchange energy is associated with the boundary between domains in ferromagnetic materials. For this reason, submicron dot samples do not energetically favor domain formation. Vortex structures have been predicted and experimentally shown to exist in these small samples. Four permalloy dot arrays (40nm thick circular dots in a square lattice with 100nm/150nm, 200nm/400nm, 500nm/550nm, and 1000nm/1100nm dot diameters/periodicities) were fabricated with e-beam lithography. Magneto-Optical Kerr Effect measurements were used to show when the vortex state was supported in the dots and to determine the anisotropy as a function of the angle between the magnetic field and dot lattice sides. Spin dynamics of the permalloy dots were also measured by ferromagnetic resonance, and additional modes besides the main resonance were shown to exist under certain conditions.

Authors

  • Dane Owen

  • Chengtao Yu

  • Michael Pechan

    Miami University, Oxford, OH 45056

  • Perry Yaney

    Department of Physics, University of Oregon, USAF Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson AFB, Ohio, NHMFL, CRIEPI, UCSD, University of Dayton, L-3 Communications Cincinnati Electronics, University of Georgia, Air Force Research Laboratory, Anteon Corporation, California State University-Chico, The Ohio State University, Univ. Akron, Air Force Institute of Technology, Albion College, Albion, MI 49224, Physics Department, University of Florida, Gainesville, Mound Laser \& Photonics Center, Inc., Hitachi Global Storage Technologies, San Jose, CA 95120, University of Dayton Research Institute, University of South Alabama, Jet Propulsion Laboratory, Anteon, Universidad Michoacana de San Nicolas de Hidalgo, Morelia, Michoac\'{a}n, Mexico, Department of Chemistry, The University of Akron, Department of Physics, The University of Akron, Physics Department and The Future-Chips Constellation, Renssalaer Polytechnic Institute, Local Co-Chair

  • Perry Yaney

    Department of Physics, University of Oregon, USAF Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson AFB, Ohio, NHMFL, CRIEPI, UCSD, University of Dayton, L-3 Communications Cincinnati Electronics, University of Georgia, Air Force Research Laboratory, Anteon Corporation, California State University-Chico, The Ohio State University, Univ. Akron, Air Force Institute of Technology, Albion College, Albion, MI 49224, Physics Department, University of Florida, Gainesville, Mound Laser \& Photonics Center, Inc., Hitachi Global Storage Technologies, San Jose, CA 95120, University of Dayton Research Institute, University of South Alabama, Jet Propulsion Laboratory, Anteon, Universidad Michoacana de San Nicolas de Hidalgo, Morelia, Michoac\'{a}n, Mexico, Department of Chemistry, The University of Akron, Department of Physics, The University of Akron, Physics Department and The Future-Chips Constellation, Renssalaer Polytechnic Institute, Local Co-Chair

  • Perry Yaney

    Department of Physics, University of Oregon, USAF Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson AFB, Ohio, NHMFL, CRIEPI, UCSD, University of Dayton, L-3 Communications Cincinnati Electronics, University of Georgia, Air Force Research Laboratory, Anteon Corporation, California State University-Chico, The Ohio State University, Univ. Akron, Air Force Institute of Technology, Albion College, Albion, MI 49224, Physics Department, University of Florida, Gainesville, Mound Laser \& Photonics Center, Inc., Hitachi Global Storage Technologies, San Jose, CA 95120, University of Dayton Research Institute, University of South Alabama, Jet Propulsion Laboratory, Anteon, Universidad Michoacana de San Nicolas de Hidalgo, Morelia, Michoac\'{a}n, Mexico, Department of Chemistry, The University of Akron, Department of Physics, The University of Akron, Physics Department and The Future-Chips Constellation, Renssalaer Polytechnic Institute, Local Co-Chair