Editing Metal (section)

=== Half metal ===
{{Main|Half-metal}}
A '''half-metal''' is any substance that acts as a [[Electrical conductor|conductor]] to [[electron]]s of one [[Spin (physics)|spin]] orientation, but as an [[Electrical insulation|insulator]] or [[semiconductor]] to those of the opposite spin. They were first described in 1983, as an explanation for the electrical properties of [[manganese]]-based [[Heusler alloy]]s.<ref>{{Cite journal |last1=de Groot |first1=R. A. |last2=Mueller |first2=F. M. |last3=Engen |first3=P. G. van |last4=Buschow |first4=K. H. J. |date=1983-06-20 |title=New Class of Materials: Half-Metallic Ferromagnets |url=https://link.aps.org/doi/10.1103/PhysRevLett.50.2024 |journal=Physical Review Letters |language=en |volume=50 |issue=25 |pages=2024–2027 |doi=10.1103/PhysRevLett.50.2024 |bibcode=1983PhRvL..50.2024D |issn=0031-9007}}</ref> Although all half-metals are [[Ferromagnetism|ferromagnetic]] (or [[Ferrimagnetism|ferrimagnetic]]), most ferromagnets are not half-metals. Many of the known examples of half-metals are [[oxide]]s, [[sulfide]]s, or [[Heusler alloy]]s.<ref>{{Cite journal |last1=Coey |first1=J. M. D. |last2=Venkatesan |first2=M. |date=2002-05-15 |title=Half-metallic ferromagnetism: Example of CrO2 (invited) |url=https://pubs.aip.org/jap/article/91/10/8345/485889/Half-metallic-ferromagnetism-Example-of-CrO2 |journal=Journal of Applied Physics |language=en |volume=91 |issue=10 |pages=8345–8350 |doi=10.1063/1.1447879 |issn=0021-8979}}</ref>