Crystal structures and lattice distortions of {sigma}-type layered vanadium bronzes: {sigma}-M{sub 0.25}V{sub 2}O{sub 5}{center_dot}H{sub 2}O (M = Mg, Co, Ni)
- Kyoto Univ. (Japan)
New {sigma}-type layered vanadium bronzes M{sub 0.25}V{sub 2}O{sub 5}{center_dot}H{sub 2}O were hydrothermally synthesized for divalent metals of M = Mg, Co, Ni in addition to the first-reported M = Zn compound. The {sigma}-type structures, consisting of V{sub 2}O{sub 5} layers with three octahedral and one tetrahedral V atoms and interlayer M(H{sub 2}O){sub 4} rectangles, were confirmed by single-crystal X-ray diffractometry. The Ni compound crystallizes in the same P{bar 1} phase as the Zn compound while the Mg and Co compounds crystallize in the new P2{sub 1}/a phase of higher symmetry. The P2{sub 1}/a phases is an undistorted form of the P{bar 1} phases, where the distortion is caused by the locations of interlayer water molecules. Among four V atoms one octahedral atom is tetravalent and others are pentavalent, being consistent with the average V{sup 4.75+} valence. The M(H{sub 2}O){sub 4} is held by two apical oxygens of VO{sub 4} tetrahedra to form a regular MO{sub 6} octahedron and thus M{sup 2+} ions must fit for the octahedral oxygen coordination.
- OSTI ID:
- 349930
- Journal Information:
- Journal of Solid State Chemistry, Vol. 144, Issue 1; Other Information: PBD: Apr 1999
- Country of Publication:
- United States
- Language:
- English
Similar Records
Synthesis and crystal structure of {sigma}-Zn{sub 0.25}V{sub 2}O{sub 5} {center_dot} H{sub 2}O with a novel type of V{sub 2}O{sub 5} layer
Crystal chemistry of M[PO{sub 2}(OH){sub 2}]{sub 2}.2H{sub 2}O compounds (M=Mg, Mn, Fe, Co, Ni, Zn, Cd): Structural investigation of the Ni, Zn and Cd salts