Half-metal
A half-metal is any substance that acts as a conductor to electrons of one spin orientation, but as an insulator or semiconductor to those of the opposite orientation. Although all half-metals are ferromagnetic (or ferrimagnetic), most ferromagnets are not half-metals. Many of the known examples of half-metals are oxides, sulfides, or Heusler alloys.[1]
In half-metals, the valence band for one spin orientation is partially filled while there is a gap in the density of states for the other spin orientation. This results in conducting behavior for only electrons in the first spin orientation. In some half-metals, the majority spin channel is the conducting one while in others the minority channel is.
Some notable half-metals are chromium(IV) oxide, magnetite, and lanthanum strontium manganite (LSMO), silicon,[1] as well as chromium arsenide. Half-metals have attracted some interest for their potential use in spintronics.
References
- 1 2 Coey, J.M.D.; Venkatesan, M. (2002). "Half-metallic ferromagnetism: Example of CrO2". Journal of Applied Physics. 91 (10): 8345–8350. Bibcode:2002JAP....91.8345C. doi:10.1063/1.1447879.
- Son, Y.W.; Cohen, M.L.; Louie, S.G. (2006). Half-metallic graphene nanoribbons Nature 444: 347-349. doi:10.1038/nature05180
- http://www-users.york.ac.uk/~ah566/research/half_metals.html
- http://www.tcd.ie/Physics/People/Michael.Coey/oxsen/newsletter/january98/halfmeta.htm