Crystal Structure, Polymorphism, and Properties of the New Vanadyl Phosphate Na4VO(PO4)2
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- 作者：Rodion V. Panin ; Roman V. Shpanchenko ; Andrei V. Mironov ; Yuri A. Velikodny ; Evgeny V. Antipov ; Joke Hadermann ; Vasily A. Tarnopolsky ; Andrei B. Yaroslavtsev ; Enrique E. Kaul ; and Christoph Geibel
- 刊名：Chemistry of Materials
- 出版年：2004
- 出版时间：March 23, 2004
- 年：2004
- 卷：16
- 期：6
- 页码：1048 - 1055
- 全文大小：243K
- 年卷期：v.16,no.6(March 23, 2004)
- ISSN：1520-5002
文摘
The new vanadyl phosphate Na4VO(PO4)2 was synthesized and investigated by X-raypowder and single-crystal diffraction, high-temperature X-ray diffraction, electron diffraction,high-resolution electron microscopy, thermal analysis, magnetic susceptibility, and conductivity measurements. The compound undergoes a reversible phase transition at about 200
C. The crystal structure of low-temperature 
-Na4VO(PO4)2 was solved using X-ray single-crystal data. This phase has an orthorhombic unit cell with lattice parameters a = 16.0068(12)Å, b = 14.5129(8) Å, c = 7.0231(5) Å, S.G. Pbca, and Z = 8. The crystal structure of -Na4VO(PO4)2 is built by isolated chains formed by corner-shared V4+O6 octahedra linkedadditionally via corners by two PO4 tetrahedra. All chains in the structure are equivalent.Na cations are located between the chains in an ordered manner. High-temperature 
-Na4VO(PO4)2 also has an orthorhombic cell with lattice parameters a = 15.595(1) Å, b = 14.651(2)Å, c = 7.0262(6) Å, S.G. Ibam, and Z = 8. Electron diffraction study revealed an existenceof various structural transformations occurring in situ in the transmission electronmicroscope. In both - and -modifications, the susceptibility follows a Curie-Weiss lawwith a very small Curie-Weiss temperature, indicating a very weak magnetic exchangeamong the V4+ ions.
C. The crystal structure of low-temperature -Na4VO(PO4)2 was solved using X-ray single-crystal data. This phase has an orthorhombic unit cell with lattice parameters a = 16.0068(12)Å, b = 14.5129(8) Å, c = 7.0231(5) Å, S.G. Pbca, and Z = 8. The crystal structure of -Na4VO(PO4)2 is built by isolated chains formed by corner-shared V4+O6 octahedra linkedadditionally via corners by two PO4 tetrahedra. All chains in the structure are equivalent.Na cations are located between the chains in an ordered manner. High-temperature -Na4VO(PO4)2 also has an orthorhombic cell with lattice parameters a = 15.595(1) Å, b = 14.651(2)Å, c = 7.0262(6) Å, S.G. Ibam, and Z = 8. Electron diffraction study revealed an existenceof various structural transformations occurring in situ in the transmission electronmicroscope. In both - and -modifications, the susceptibility follows a Curie-Weiss lawwith a very small Curie-Weiss temperature, indicating a very weak magnetic exchangeamong the V4+ ions.