Identification of Magnetic Materials By Discrete Fourier Analysis

Abstract

A novel approach, linking microstructural effects, magnetic measurements, and signal processing methods, was developed to analyze, identify and compare magnetic materials. The Discrete Fourier Transform (DFT) was applied to DC remanent magnetization curves (RHL) and to Switching Field Distribution (SFD). It was shown analytically how the an, bn Fourier coefficients depend on the width of SFD, on the coercivity, and on the highest applied field. The field and the coercivity dependences can be separated by using complex Fourier coefficients. The effects of magnetic and sampling parameters on the DFT were numerically simulated. Based on the results of the analytical and numerical study, a measurement and DFT protocol was developed to analyze magnetic materials. The sensitivity of DFT to magnetic markers was investigated numerically, by varying the matrix/marker ratio and the relative coercivities. The measurement and FFT protocol was applied to commercial magnetic media (DELTACARD, METROCARD) and Fe-Zn nanocomposites. The results are submitted to two international conferences. Participation in this complex research gave a significant contribution to the education of two graduate and one undergraduate students..

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Feb 20, 2003
Accession Number
ADA414719

Entities

People

  • Martha Pardavi-horvath

Organizations

  • George Washington University

Tags

DTIC Thesaurus Topics

  • Coercivity
  • Composite Materials
  • Discrete Fourier Transforms
  • Electrical Engineering
  • Fourier Analysis
  • Fourier Transformation
  • Gaussian Distributions
  • Identification
  • Laboratory Magnetometers
  • Magnetic Fields
  • Magnetic Materials
  • Magnetic Properties
  • Materials
  • Measurement
  • Nanocomposites
  • Signal Processing
  • Spectra

Readers

  • Approximation Theory.
  • Superconducting Magnet Technology