ROOT LOCUS METHOD FOR PLOTTING HYSTERESIS LOOPS OF FERROMAGNETIC THIN FILMS

Abstract

A GRAPHICAL METHOD IS GIVEN TO PLOT HYSTERESIS LOOPS OF FERROMAGNETC THIN FILMS UNDER GIVEN CONDITIONS OF APPLIED PERPENDICULAR FIELD, STRESS AND INITIAL VALUE OF ANGLE BETWEEN THE EASY MAGNETIZATION AXIS AND THE SWITCHING FIELD. THE METHOD IS BASED ON A ROOT LOCUS TECHNIQUE USED TO EXTRACT THE ROOTS OF A POLYNOMIAL DERIVED FROM THE SIMPLE ROTATIONAL MODEL OF MAGNETIZATION.THE ROOT LOCUS IS READILY OBTAINED BY MEANS OF A SPIRULE AND ANY COMBINATION OF PARAMETERS MAY BE INVESTIGATED. IN PARTICULAR, TWO DIMENSIONAL STRESSES AND ISOTROPIC STRESSES MAY BE CONSIDERED. SOME INTERESTING ANALOGIES BETWEEN THE LOCUS OF ROOTS AND A HYSTERESIS LOOP MAY BE MADE, SUCH AS REAL AXIS BREAK-AWAY POINTS AND COERCIVE FORCE, SINCE AT SUCH POINTS TWO REAL ROOTS BECOME COMPLEX AND CORRESPONDINGLY, THERE IS ONLY ONE VALUE OF INDUCTION FOR A VALUE OF APPLIED SWITCHING FIELD. THE ACCURACY OBTAINED BY USE OF THE SPIRULE HAS BEEN CHECKED BY A DIGITAL COMPUTER AND IS LIMITED ONLY BY THE GRAPHICAL SKILL OF THE PLOTTER

Document Details

Document Type
Technical Report
Publication Date
Nov 01, 1960
Accession Number
AD0250151

Entities

People

  • Arthur A. Borsei

Organizations

  • University of California, Los Angeles

Tags

DTIC Thesaurus Topics

  • Accuracy
  • Coercivity
  • Computers
  • Digital Computers
  • Films
  • Hysteresis
  • Magnetization
  • Plotters
  • Plotting
  • Polynomials
  • Switching
  • Thin Films
  • Two Dimensional

Fields of Study

  • Mathematics

Readers

  • Control Systems Engineering.
  • Superconducting Magnet Technology