title: Ba2F2Fe2+ 0.5Fe3+ S3: a two-dimensional inhomogeneous mixed valence iron compound.
abstract: The structure of the new mixed valence compound Ba2F2Fe1.5S3 was solved by means of single crystal X-ray analysis. It crystallizes in an orthorhombic cell, in the Pnma space group with the cell parameters a = 12.528(3) A, b = 18.852(4) A, and c = 6.0896(12) A. The structure is formed by the alternated stacking of fluorite type [Ba2F2]2+ blocks and the newly discovered [Fe1.5S3]2- blocks. This [Fe1.5S3]2- block exhibits a mixed valence of iron with Fe(+II) located in octahedrons and Fe(+III) in tetrahedrons. Preliminary susceptibility measurements suggest a low dimensional antiferromagnetic behavior.
authors.affiliation: Institut des Matériaux Jean Rouxel (IMN), Université de Nantes, CNRS, 2 rue de la Houssinière B.P. 32229, 44322 Nantes Cedex 3, France. h.kabbour@fkf.mpg.de
authors.forename: Houria
authors.initials: H
authors.lastname: Kabbour
authors.forename: Laurent
authors.initials: L
authors.lastname: Cario