NASICON-Type Structures

However, the conductivity (1.07 x 10 Sem at 600°C) of Sci/3Zr2(PO4)3 synthesized with the sol-gel technique was low in comparison with that of Sc2(WO4)3 tungstate (3.74 x 10 S cm at 600 °C), largely because SC /3Zr2(PO4)3 obtained via the sol-gel method has a low crystallinity. In addition, the crystallization (at ca. 800 °C) and decomposition temperatures (ca. 950 °C) of Sciy3Zr2(PO4)3 were close, and any improvement in the crystallinity seemed difEcult to achieve when using a 

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Wang, S. andHwu, S., Li3 xTi2(P04)3 (0valent titanium (Ill/fV) phosphate with a NASICON-type structure, J. Solid State Chem., 90, 377, 1991. 

While some of these compounds have Nasicon-type structures (Chapter 12.19), others are tung-sten-bronze-type materials, containing and Nb + with continuously connected NbOg octahe-dra which allow electron conduction. 

Some Compounds with NZP or Nasicon-Type Structures... 

Hasegawa Y, Tamura S, Imanaka N, Adachi G, Takano Y, Sekizawa K (2004) Trivalent praseodymium ion conducting solid electrolyte composite with NASICON type structure. J Alloys Compd 375 212-216... 

In addition to apatite and the AlPO -modifications, phosphates of the nasicon-type structure are also important in silica-free phosphate glass-ceramics. Winand et al. (1990), have shown that Na IiCPOj) belongs to the nasicon-type structure of Naj Zr2P3 j Si 0 2- The space group is Rdc. Divalent ions may also be inserted into these structures without changing the nasicon structure. According to Schulz et al. (1994), the complex structural formula can be written as follows ... 

Fig. 5 Structural representation of the NASICON-type structure of a LiTi2(P04)a (space group R-3c) showing the Li ions channels along the a axis b Ii3Ti2(P04)3 (space group R-3) showing the Li sites partially occupied [26]. Legend yellow phosporus, violet— lithium, blue titanium, red —oxygen (Color figure online)...

Zhang P, Matsui M, Hirano A, Takeda Y, Yamamoto O, Imanishi N (2013) Water-stable lithium ion conducting solid electrolyte of the Lii 4Alo.4Tii g xGex(P04)3 system (x = 0-1.0) with NASICON-type structure. Solid State Ionics 253 175... 

Table 7.5 Properties of lithium-msertion compounds with the NASICON-type structure...

Fig. 7.28 Schematic representation of NASICON-type structure (a) rhombohedral and (b) monoclinic...

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