Accession Number:

ADA300544

Title:

Uncompensated Garnets: A Magnetic Semiconductor.

Descriptive Note:

Rept. for 1 Mar 91-31 Dec 94,

Corporate Author:

OHIO STATE UNIV COLUMBUS DEPT OF PHYSICS

Personal Author(s):

Report Date:

1995-05-09

Pagination or Media Count:

36.0

Abstract:

Yttrium iron garnet YIG is a ferrimagnetic oxide, Y3Fe5O12 and a good insulator. When five to ten percent of the Y3 is replaced by Ca2, 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 ohm 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 in samples that have been annealed in a reducing atmosphere. The reduction process introduces oxygen vacancies which should compensate the hole introduced by Ca2. 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.

Subject Categories:

  • Geology, Geochemistry and Mineralogy
  • Inorganic Chemistry
  • Electrical and Electronic Equipment
  • Electricity and Magnetism
  • Optics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE