Crystal Structure of Ba sub 27 Fe sub 16 Ti sub 33 O sub 117

Single-crystal X-ray diffraction studies indicate that the compound Ba sub 27 Fe sub 16 Ti sub 33 O sub 117 crystallizes in the rhombohedral space group R3m, with a hexagonal unit cell a=5.7400(8) A, c=127.11(3) A; Z=1.5, The arrangement may be described as a 54-layer (54L) close-packed structure (stacking sequence (cch) sub 18) built from oxygen and {Ba,O} layers, with Ti sup 4+ occupying octahedra and Fe sup 3+ occupying both octahedral and tetrahedral interstices.