Cation vacancy order in the K0.8+xFe1.6−ySe2 system: five-fold cell expansion accommodates 20% tetrahedral vacancies

Bacsa, J., Ganin, A.Y. , Takabayashi, Y., Christensen, K.E., Prassides, K., Rosseinsky, M.J. and Claridge, J.B. (2011) Cation vacancy order in the K0.8+xFe1.6−ySe2 system: five-fold cell expansion accommodates 20% tetrahedral vacancies. Chemical Science, 2(6), pp. 1054-1058. (doi: 10.1039/c1sc00070e)

Abstract

Ordering of the tetrahedral site vacancies in two crystals of refined compositions K0.93(1)Fe1.52(1)Se2 and K0.862(3)Fe1.563(4)Se2 produces a fivefold expansion of the parent ThCr2Si2 unit cell in the ab plane which can accommodate 20% vacancies on a single site within the square FeSe layer. The iron charge state is maintained close to +2 by coupling of the level of alkali metal and iron vacancies, producing a potential doping mechanism which can operate at both average and local structure levels.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Ganin, Dr Alexey
• Authors: Bacsa, J., Ganin, A.Y., Takabayashi, Y., Christensen, K.E., Prassides, K., Rosseinsky, M.J., and Claridge, J.B.
• College/School: College of Science and Engineering > School of Chemistry
• Journal Name: Chemical Science
• ISSN: 2041-6520