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

DOI: 10.1039/c1sc00070e

Authors: John Bacsa (University of Liverpool) , Alexey Ganin (University of Liverpool) , Yasuhiro Takabayashi (University of Durham) , Kirsten Christensen (Diamond Light Source) , Kosmas Prassides (University of Durham) , Matthew Rosseinsky (University of Liverpool) , John Claridge (University of Liverpool)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Chemical Science

State: Published (Approved)
Published: March 2011

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.

Subject Areas: Materials, Chemistry


Instruments: I19-Small Molecule Single Crystal Diffraction

Added On: 26/04/2011 12:23

Discipline Tags:

Superconductors Quantum Materials Physical Chemistry Chemistry Materials Science

Technical Tags:

Diffraction Single Crystal X-ray Diffraction (SXRD)