Sources of Anisotropy in Amorphous Magnetic Thin Films

Abstract

With the assistance of this grant, my laboratory has progressed substantially and is now beginning to produce results. This last year, in addition to lab build-up and student supervision, I have continued work on the amorphous rare earth transition metal alloys. There are several significant new results arising from this work. A model for the growth-induced macroscopic magnetic anisotropy: I have clear evidence against Takeshi Egami's Bond- Orientational Anisotropy model which attributes the anisotropy to anelastic strain . He describes this model as a simple increase in the number of bonds in- plane compared to out-of-plane due to stress during the growth. I find a strong (more than an order of magnitude) dependence of the anisotropy on deposition temperature and essentially no dependence on the state of stress either during the growth or after. I believe the reason for the anisotropy is a texturing of the short-range order relative to the surface, which minimizes surface energy at every instant during the growth, and gets frozen into the structure.

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Document Details

Document Type
Technical Report
Publication Date
Nov 17, 1990
Accession Number
ADA230542

Entities

People

  • Frances Hellman

Organizations

  • University of California, San Diego

Tags

Communities of Interest

  • Advanced Electronics

DTIC Thesaurus Topics

  • Abstracts
  • Alloys
  • Curie Temperature
  • Films
  • Laboratory Magnetometers
  • Magnetic Anisotropy
  • Magnetic Fields
  • Magnetic Films
  • Magnetic Materials
  • Magnetic Properties
  • Materials
  • Materials Science
  • Measurement
  • Phase
  • Specific Heat
  • Thin Films
  • Transitions

Readers

  • Materials Science and Engineering.
  • Quantum spin resonance or Electron Paramagnetic Resonance spectroscopy.
  • Structural Dynamics.