Electrical & Computer Engineering Research Works

Permanent URI for this collectionhttp://hdl.handle.net/1903/1658

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Author: search.filters.author.Gomez, R. D.End date: 1999

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Now showing 1 - 5 of 5
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    Analytical solution for the side-fringing fields of narrow beveled heads
    (American Institue of Physics, 1997-04-15) Mayergoyz, I. D.; Madabhushi, R.; Burke, E. R.; Gomez, R. D.
    By using conical coordinates, exact analytical solutions for three-dimensional side-fringing fields of recording heads that are beveled in the down-track direction are found. These solutions are derived under the assumption of zero gap length. The side-fringing fields for the two limiting cases of infinitesimally narrow heads and semi-infinitely wide heads are presented and compared.
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    Switching characteristics of submicron cobalt islands
    (American Institute of Physics, 1996-07-01) Gomez, R. D.; Shih, M. C.; New, R. M. H.; Pease, R. F. W.; White, R. L.
    The magnetic characteristics of 0.230.430.02 mm3 cobalt islands were investigated using magnetic force microscopy in the presence of an applied field. The islands were noninteracting and showed a wide variety of single and multidomain configurations. The distribution of magnetization directions supports earlier models which suggest that crystalline anisotropy plays a dominant role in establishing a dispersion of easy axis directions about the long axis of the particles. The magnetic evolution, involving rotation and switching of individual islands, was observed at various points along the microscopic magnetization curve. A magnetization curve of an ensemble of islands was derived from the images and compares remarkably well with macroscopic M–H measurements.
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    Domain wall motion in micron-sized Permalloy elements
    (American Institute of Physics, 1999-04-15) Gomez, R. D.; Luu, T. V.; Pak, O. A.; Mayergoyz, I. D.; Kirk, K. J.; Chapman, J. N.
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    Domain configurations of Permalloy elements
    (American Institute of Physics, 1999-04-15) Gomez, R. D.; Luu, T. V.; Pak, A. O.; Kirk, K. J.; Chapman, J. N.
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    Quantification of magnetic force microscopy images using combined electrostatic and magnetostatic imaging
    (American Institute of Physics, 1998-06-01) Gomez, R. D.; Pak, A. O.; Anderson, A. J.; Burke, E. R.; Leyendecker, A. J.; Mayergoyz, I. D.
    A method for calibrating the force gradients and probe magnetic moment in phase-contrast magnetic force microscopy ~MFM! is introduced. It is based upon the combined electrostatic force microscopy EFM and MFM images of a conducting non magnetic metal strip. The behavior of the phase contrast in EFM is analyzed and modeled as a finite area capacitor. This model is used in conjunction with the imaging data to derive the proportionality constant between the phase and the force gradient. This calibration is further used to relate the measured MFM images with the field gradient from the same conducting strip to derive the effective magnetic moment of the probe. The knowledge of the phase-force gradient proportionality constant and the probe’s effective moment is essential to directly quantify field derivatives in MFM images.