X-ray structural investigation of the oxyvanite (V3 O5) berdesinskiite (V2 TiO5) series: V4+ substituting for octahedrally coordinated Ti4+
Armbruster, Thomas; Galuskin, Evgeny V.; Reznitsky, Leonid Z.; Sklyarov, Evgeny V.
European Journal of Mineralogy Volume 21 Number 4 (2009), p. 885 - 891
published: Aug 1, 2009
ArtNo. ESP147052104018, Price: 29.00 €
The crystal structures of three different solid-solution members between the new mineral oxyvanite (V3 O5) - and berdesinskiite (V2 TiO5 ) from a quartzite rock in the Pereval marble quarry of the Sludyanka complex, south of Lake Baikal (Russia), have been refined in space group C 2/ c (a ≈ 10.0, b 5.0, c ≈ 7.0 Å , β ≈ 111°) from X-ray single-crystal diffraction-data. The composition of the studied crystals, determined by electron-microprobe analyses, is: (V3+1.67 Cr3+0.33(V4+0.59 Ti4+0.41)O5,(V3+1.67Cr3+0.33)(V4+0.46Ti4+0.54) O5, and (V3+1.38Cr3+0.61)(V4+0.24Ti4+0.76O5 . The common structure type of oxyvanite and berdesinskiite can be described by hexagonal closest oxygen packing with 3/5 of the octahedral voids occupied. Site-occupancy refinements support previous studies on synthetic V2 TiO5 and V3 O5 indicating that a strongly distorted octahedrally coordinated site, forming pairs of face-sharing octahedra, is 1:1 occupied by M3+ and M4+ (Ti4+, V4+) whereas a more regular octahedral site is only occupied by M3+ (V, Cr).