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Half-Metallic Ferromagnetic Oxides

Published online by Cambridge University Press:  31 January 2011

J.M.D. Coey  and
C.L. Chien
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Abstract

Half-metals are unusual ferromagnets that have electrons at the Fermi level in a single spin state, either spin up or spin down. Of potential interest as sources and analyzers of polarized electrons in spintronic devices, they are usually identified from spin-dependent band-structure calculations. We present a classification scheme for half-metals and then discuss methods for measuring spin polarization based on point contacts or tunnel junctions with ferromagnetic or superconducting counter electrodes. Oxide examples include CrO2, the best-studied half-metal. The half-metallicity tends to be destroyed by increasing temperature and by structural defects. The half-metals that currently offer the best prospects for spintronics applications are those with the highest Curie temperatures, such as magnetite, Fe3O4, and perhaps oxide semiconductors such as Co-doped ZnO.

Keywords

Andreev reflectionCrO2Fe3O4ferromagnetic oxideshalf-metalsspin-polarized materialsspintronicstunneling
Type
Research Article
Information
MRS Bulletin , Volume 28 , Issue 10: New Materials for Spintronics , October 2003 , pp. 720 - 724
Copyright
Copyright © Materials Research Society 2003

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