Uncompensated Garnets: A Magnetic Semiconductor.

Abstract

Yttrium iron garnet (YIG) is a ferrimagnetic oxide, Y3Fe5O12 and a good insulator. When five to ten percent of the Y(3+) is replaced by Ca(2+), an uncompensated state exists. The resulting material has perturbed magnetic properties, semiconducting electrical properties with activation energies from 0.2 to 0.4 eV and resistivities as low as 300 ohms cm at room temperature, and modified optical properties. In the past year the conductivity studies have concentrated on the evolution of a high conduction state m samples that have been annealed in a reducing atmosphere. The reduction process introduces oxygen vacancies which should compensate the hole introduced by Ca(2+). The annealing is also observed to modify significantly the effective exchange constant of the material and the optical activity. These measurements are summarized in this report.

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Document Details

Document Type
Technical Report
Publication Date
May 09, 1995
Accession Number
ADA300800

Entities

People

  • Philips E. Wigen

Organizations

  • Ohio State University

Tags

Communities of Interest

  • Advanced Electronics
  • Biomedical

DTIC Thesaurus Topics

  • Absorption Spectra
  • Annealing
  • Atmospheres
  • Conductivity
  • Crystal Lattices
  • Curie Temperature
  • Electrical Properties
  • Energy
  • Energy Bands
  • Heat Of Activation
  • High Temperature
  • Low Temperature
  • Magnetic Properties
  • Materials
  • Measurement
  • Optical Properties
  • Semiconductors

Fields of Study

  • Materials science

Readers

  • Materials Science and Engineering.

Technology Areas

  • Microelectronics
  • Microelectronics - Graphene