Structural chemistry of a new 10H hexagonal perovskite: BaMn 0.4Fe0.6O2.73

Abstract

A new 10H polytype has been stabilized in the BaMn1-x-Fe xO3-y system with the composition BaMn 0.4Fe0.6O2.73. The anionic composition has been established by a reduction and re-oxidation cycle in the stability range of this phase. The structural characterization was carried out by high-resolution electron microscopy (HREM), electron diffraction, and X-ray diffraction. The structure is closely related to the ideal (hch′ch)2 10H polytype with two oxygen-deficient hexagonal (h′) BaO2-y layers per unit formula. This framework gives rise to blocks of three octahedra sharing faces linked by corners to two corner-sharing tetrahedra. © Wiley-VCH Verlag GmbH & Co. KGaA, 2007.