Iron(II,III) sulfide

Iron(II,III) sulfide is a blue-black (sometimes pinkish) chemical compound of iron and sulfur with formula Fe3S4 or FeS·Fe2S3, which is much similar to iron(II,III) oxide. It occurs naturally as the sulfide mineralgreigite and is magnetic. It is a bio-mineral produced by and found in magnetotactic bacteria. It is a mixed valence compound, featuring both Fe2+ and Fe3+ centers, in 1:2 ratio.

Crystal structure

The crystallographic unit cell is cubic, with space group Fd3m. The S anions form a cubic close-packed lattice, and the Fe cations occupy both tetrahedral and octahedral sites.[1][2]

Magnetic and electronic properties

Like the related oxide magnetite (Fe3O4), iron(II,III) sulfide is ferrimagnetic, with the spin magnetic moments of the FeIII centers in the tetrahedral sites oriented in the opposite direction as those in the octahedral sites, and a net magnetization. Both metal sites have high spin quantum numbers. The electronic structure of greigite is that of a half metal.[3][4]

References

  1. Anthony, John W.; Bideaux, Richard A.; Bladh, Kenneth W.; Nichols, Monte C., eds. (1990). "Greigite"(PDF). Handbook of Mineralogy. Vol. I (Elements, Sulfides, Sulfosalts). Chantilly, VA, US: Mineralogical Society of America. ISBN 978-0-9622097-0-3. Retrieved December 5, 2011.
  2. Vaughan, D. J.; Craig, J. R. "Mineral Chemistry of Metal Sulfides" Cambridge University Press, Cambridge: 1978. ISBN 0-521-21489-0.
  3. ↑ ديفي، أنتوني؛ غراو-كريسبو ، ر.؛ دي ليو، ن . هـ. (2009). "البنية الإلكترونية والمغناطيسية لـ Fe3S4 : دراسة باستخدام تقريب التدرج المعمم + U". مجلة Physical Review B. 79 ( 19) 195126. Bibcode : 2009PhRvB..79s5126D . doi : 10.1103/PhysRevB.79.195126 .
  4. ↑ وانغ، جون؛ كاو ، شي-هي؛ وو، وي؛ تشاو، غو-مينغ (2011). "درجة حرارة كوري وطاقة التبادل المغناطيسي في الجريجيت شبه المعدني Fe3S4 " . فيزيكا سكريبت . 83 (4) 045702. Bibcode : 2011PhyS...83d5702W . doi : 10.1088/0031-8949/83/04/045702 .

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