Iron arsenide

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Iron arsenides are chemical compounds between iron and arsenic . In some cases, other compounds with other elements are also included in these. This includes, for example, a class of high temperature superconductors such as BaFe 2 As 2 and 122 iron arsenide superconductors.

Iron arsenides are found in nature as a mineral Löllingit (FeAs 2 ) Westerveldit (FeAs) and Ferroskutterudit (FeAs 3 ).

properties

The component elements form four compounds, namely the tetragonal Fe 2 As, the Fe 3 As 2 , which only exists above 824 ° C , the orthorhombic FeAs with a manganese phosphide structure and the orthorhombic FeAs 2 . The existence of pure FeAs 3 is not considered to be certain, since the phase diagram does not show this. In chemical analyzes, the corresponding mineral ferroscutterudite showed a composition that, in addition to iron, also contained a large proportion of cobalt and small amounts of nickel and sulfur (for example Fe 0.600 Co 0.394 Ni 0.002 As 2.888 S 0.116 ). FeAs 2 is a diamagnetic semiconductor with a band gap of 0.22 eV.

Iron arsenide
Surname Iron arsenide Iron diarsenide Iron triarsenide Iron arsenide
other names Westerveldite
iron (III) arsenide 		Lollingite Ferro cutter audit
CAS number 12044-16-5 12006-21-2 12005-88-8
PubChem 82876 71310805 71310806
Molecular formula FeAs FeAs 2 FeAs 3 Fe 2 As
Molar mass 130.77 g mol −1 205.69 g mol −1 280.61 g mol −1 186.61 g mol −1
Physical state firmly
Brief description white solid odorless gray solid
Melting point 1020 ° C 990 ° C > 400 ° C
boiling point
density 7.83 g cm −3 7.4 g cm −3
solubility slightly soluble in water practically insoluble in water
GHS
labeling
06 - Toxic or very toxic 09 - Dangerous for the environment
danger
06 - Toxic or very toxic 09 - Dangerous for the environment
danger
no classification available
06 - Toxic or very toxic 09 - Dangerous for the environment
danger
H and P phrases 301-331-410 301-331-410 see above 301-331-410
261-273-301 + 310-311-501 261-273-301 + 310-311-501 see above 261-273-301 + 310-311-501

presentation

The iron arsenides FeAs and FeAs 2 can be produced by electrolysis of melts made of iron (III) oxide or iron (III) chloride and alkali metal arsenates . Direct synthesis from the elements is also possible.

Individual evidence

  1. ↑ Max Planck Society: Iron Arsenide Superconductors - An Example of the Central Role of Crystal Growing in Solid State Research , accessed on May 30, 2018
  2. ↑ James Huheey, Ellen Keiter, Richard Keiter: Inorganic chemistry principles of structure and reactivity . Walter de Gruyter GmbH & Co KG, 2014, ISBN 978-3-11-037400-1 , p. 301 ( limited preview in Google Book search).
  3. ^ A b O. Kubaschewski: IRON — Binary Phase Diagrams . Springer Science & Business Media, 2013, ISBN 978-3-662-08024-5 , p. 10 ( limited preview in Google Book search).
  4. ↑ Ferroscutterudite . In: John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols (Eds.): Handbook of Mineralogy, Mineralogical Society of America . 2001 ( handbookofmineralogy.org [PDF; accessed May 31, 2018]).
  5. ↑ Stefan Kiefer, Juraj Majzlan, Martin Chovan, Martin Števko: Mineral compositions and phase relations of the complex sulfarsenides and arsenides from Dobšiná (Western Carpathians, Slovakia) . In: Ore Geology Reviews . tape 89 , 2017, p. 894 , doi : 10.1016 / j.oregeorev.2017.07.026 .
  6. ^ Albert KL Fan, Gerald H. Rosenthal, Howard L. McKinzie, Aaron Wold: Preparation and properties of FeAs 2 and FeSb 2 . In: Journal of Solid State Chemistry . tape 5 , 1972, p. 136 , doi : 10.1016 / 0022-4596 (72) 90021-7 .
  7. ↑ a b c d Dale L. Perry: Handbook of Inorganic Compounds, Second Edition . CRC Press, 2016, ISBN 978-1-4398-1462-8 , pp. 214 ( limited preview in Google Book search).
  8. ↑ a b Data sheet Iron arsenide, 99.5% (metals basis) at AlfaAesar, accessed on May 30, 2018 ( PDF )(JavaScript required) .
  9. ↑ a b c data sheet Iron diarsenide, pieces, 99.5% trace metals basis at Sigma-Aldrich , accessed on May 30, 2018 ( PDF ).
  10. ↑ a b Datasheet Iron arsenide, pieces, 99.5% trace metals basis at Sigma-Aldrich , accessed on May 30, 2018 ( PDF ).
  11. ↑ Data sheet Iron (III) arsenide, 99.5% trace metals basis from Sigma-Aldrich , accessed on May 30, 2018 ( PDF ).
  12. ↑ Paul Hagenmuller: Preparative Methods in Solid State Chemistry . Elsevier, 2012, ISBN 0-323-14436-5 , pp. 299 ( limited preview in Google Book search).