backup of oxypnictide by Stone before edit failed.
In chemistry, oxypnictides are a class of materials including oxygen, a pnictogen (group-V, especially phosphorus and arsenic) and one or more other elements.
The interest in this group of compounds results from the superconducting properties which were discovered 2006[1] and 2008[2].[3]
Structure edit
For example LaOFeP has a layered structure with layers of La3+02- and Fe2+P3-.[1]
Superconductor edit
The first superconducting iron oxypnictide was discovered in 2006, based on phosphorus.[1] A drastic increase in the critical temperature was achieved when phosphorus was substituted by arsenic[2]. This discovery boosted the search for similar compounds, like the search for cuprate-based superconductors after their discovery in 1986.
Some found in 2008 to be high temperature superconductors (at 43 K) of composition ReOTmPn where Re is a rare earth, Tm is a transition metal and Pn is from group-V eg As.[4]
Tests at up to 45 Tesla[5] [6]suggest the upper critical field of LaFeAsO0.89F0.11 may be around 64 Tesla.
References edit
- ^ a b c Yoichi Kamihara, Hidenori Hiramatsu, Masahiro Hirano, Ryuto Kawamura, Hiroshi Yanagi, Toshio Kamiya, and Hideo Hosono (2006). "Iron-Based Layered Superconductor: LaOFeP". J. Am. Chem. Soc. 128 (31): 10012–10013. doi:10.1021/ja063355c S0002-7863(06)03355-5.
{{cite journal}}: Check|doi=value (help)CS1 maint: multiple names: authors list (link) - ^ a b Hiroki Takahashi, Kazumi Igawa, Kazunobu Arii, Yoichi Kamihara, Masahiro Hirano, Hideo Hosono (2008). "Superconductivity at 43 K in an iron-based layered compound LaO1-xFxFeAs". Nature. 453: 376–378. doi:10.1038/nature06972.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ Charles Day (2008). "New family of quaternary iron-based compounds superconducts at tens of kelvin". Physics Today. 61 (5): 11–12. doi:10.1063/1.2930719.
- ^ "Samarium based SmFeAsO1−xFx".
- ^ http://www.planetanalog.com/news/showArticle.jhtml?articleID=208401297
- ^ http://www.nature.com/nature/journal/v453/n7197/abs/nature07058.html