Spin electronics using on half-metals

Rudolf Gross

Walther-Meissner-Institute, 
Bavarian Academy of Sciences and Technical University of Munich, 
D-85748 Garching, Germany
http://www.wmi.badw.de

The field of spin electronics has attracted broad interest over recent years due to a variety of both interesting physical phenomena and promising applications. The efficient use of the spin degree of freedom of charge carriers in “spintronic” devices requires materials with high spin polarization of the charge carriers at the Fermi level. Furthermore, for room temperature applications ferromagnetic materials with sufficiently high Curie temperature are desirable. These requirements have stimulated the interest in half-metallic ferromagnets with Curie temperatures well above room temperature. Besides the Heusler compounds, promising candidates are various transition metal oxides such as the doped manganites, magnetite (Fe3O4), or the double perovskites (A2BB’O6 with A= Sr, Ba, Ca and BB’ = CrW, FeMo, FeRe). We discuss the state of development of various half-metallic materials with respect to the underlying physics, the fabrication technology and the application in simple device structures.