Ionic conductivities of crystalline and glassy Na4NbP3O12 and crystalline Na6Nb2P6O23

Wang, B.; Greenblatt, Martha; Yan, Jian

doi:10.1016/0167-2738(94)90454-5

Cited by 8 publications

(12 citation statements)

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“…El Jazouli et al 13 compared the Raman spectra of Na 4 NbP 3 O 12 glass and crystal, and concluded that the structure of the glass and the crystal are very similar and consistent with NASICON-type structure with distorted and isolated PO 4 tetrahedra. Wang et al 16 from their IR spectroscopic study of NNP glass and crystal concluded that the crystal consisted of pyrophosphate units which were present in the glass also. While Wang et al 16 attributed the 1175 cm -1 band to pyrophosphate units, Krimi et al 15 associated the weak 1027 cm -1 stretching mode with [P 2 O 7 ] 4-.…”

Section: 3a Evidence For [P 2 O 7 ] 4speciesmentioning

confidence: 99%

“…Wang et al 16 from their IR spectroscopic study of NNP glass and crystal concluded that the crystal consisted of pyrophosphate units which were present in the glass also. While Wang et al 16 attributed the 1175 cm -1 band to pyrophosphate units, Krimi et al 15 associated the weak 1027 cm -1 stretching mode with [P 2 O 7 ] 4-. The spectra of NNP (also KNP) glass in figure 4 are in very good agreement with those of Wang et al 16 .…”

Section: 3a Evidence For [P 2 O 7 ] 4speciesmentioning

confidence: 99%

“…While Wang et al 16 attributed the 1175 cm -1 band to pyrophosphate units, Krimi et al 15 associated the weak 1027 cm -1 stretching mode with [P 2 O 7 ] 4-. The spectra of NNP (also KNP) glass in figure 4 are in very good agreement with those of Wang et al 16 . The 1180 cm -1 band due to P-O stretching along with the 725 cm -1 band due to P-O-P bending may be considered as evidence for the presence of [P 2 O 7 ] 4in our glasses as well.…”

Section: 3a Evidence For [P 2 O 7 ] 4speciesmentioning

confidence: 99%

“…Very few reports have appeared in the literature on the vibrational spectra of this class of phosphate glasses. Some of the reported spectra refer to either a single glass composition or to the study of the systematic variation of composition with respect to one of the constituent oxides [13][14][15][16][17] .…”

Section: Introductionmentioning

confidence: 99%

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Infrared and Raman spectroscopic studies of glasses with NASICON-type chemistry

2001

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Structures of NASICON glasses of the general formula AB 2 (PO 4) 3 , where A = Li, Na or K and B = Fe, Ga, Ti, V or Nb, have been investigated using vibrational (IR and Raman) spectroscopies. Phosphate species appear to establish an equilibrium via a disproportionation reaction involving a dynamical bond-switching mechanism where both charge and bonds are conserved. B ions in the system acquire different coordinations to oxygens. Alkali ions cause absorptions due to cage vibrations. All the observed spectroscopic features are consistent with speciation involving disproportionation reactions. Keywords. NASICON glasses; dynamical bond-switching mechanism; disproportionation reactions. share corners with PO 4 tetrahedra. NASICONs possess 'open' structures in which alkali ions can move with significantly reduced activation barriers and hence the potential for applications as fast ion conductors. Since the B site can be substituted by a variety of transition and non-transition metals (and their combinations) with appropriate charge compensation in the structure by additional alkali ions, NASICONs constitute a very versatile class of materials 3-5. NASICONs by virtue of their complex chemistry have a built-in propensity to form good glasses, (especially when the material is a phosphate). Higher valent elements such as vanadium (V) or niobium (Nb) increase the covalency of the B-O linkage and facilitate the formation of glasses. A number of NASICON glasses have been investigated 6-9 in this laboratory. It has been found that contrary to expectations, the molar volumes of glasses with NASICON chemistry are sensitive to the size of the alkali ion to a much greater extent than their crystalline counterparts. Indeed, in the absence of the requirement of crystalline periodicity, the network structure collapses around the alkali ions, eliminating the 'openness' of the structure, and the observed conductivities are rather low. Additionally, the coordination numbers of the B ions also vary, facilitating the formation of different types of phosphate species, which have been identified 10 by 31 P MAS NMR.

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Section: 3a Evidence For [P 2 O 7 ] 4speciesmentioning

confidence: 99%

Section: 3a Evidence For [P 2 O 7 ] 4speciesmentioning

confidence: 99%

Section: 3a Evidence For [P 2 O 7 ] 4speciesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Infrared and Raman spectroscopic studies of glasses with NASICON-type chemistry

2001

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“…NASICONs are also important for their ''net zero thermal expansion'' behavior (5). It has been found that some NASICON-type chemical compositions (with the general formula A V B W P O ) can be vitrified, and several studies have reported on the resulting glasses (6,7). However, the procedures presently available for the preparation of both crystalline and glassy NASICON materials are tedious and involved.…”

Section: Introductionmentioning

confidence: 97%

High Microwave Susceptibility of NaH2PO4·2H2O: Rapid Synthesis of Crystalline and Glassy Phosphates with NASICON-Type Chemistry

Vaidhyanathan

Rao

1997

Journal of Solid State Chemistry

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Preparation, characterization and conductivity studies of a Nasicon system Ag_3–2xTa_x Al_2–x (PO₄)₃ (x = 0.6–1.4)

Gundla

Anantharamulu

Rao

et al. 2007

Physica Status Solidi (a)

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Rhombohedral Nasicon type materials of composition Ag3–2x Tax Al2–x (PO4)3 (x = 0.6, 0.7,0.8, 0.9, 1.0, 1.1,1.2, 1.3 and 1.4) have been prepared and characterized by powder XRD and IR. All these compositions are found to be isomorphous with NbTiP3O12, lithium and sodium analogues of same Nasicon framework. The unit cell parameters were derived from powder XRD. All the compounds show characteristic PO4 vibrational bands. DC conductivity measurements were carried out in the temperature range 300–650 K. The activation energies for conduction were deduced from the Arrhenius plots and are in the range 0.42–0.71 eV. Among the series investigated, Ag0.8Ta1.1Al0.9P3O12 exhibits the highest conductivity, σ ≈ 5.01 × 10–3 S cm–1 at 350 °C (Ea = 0.55 eV). (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

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Ionic conductivities of crystalline and glassy Na4NbP3O12 and crystalline Na6Nb2P6O23

Cited by 8 publications

References 13 publications

Infrared and Raman spectroscopic studies of glasses with NASICON-type chemistry

Infrared and Raman spectroscopic studies of glasses with NASICON-type chemistry

High Microwave Susceptibility of NaH2PO4·2H2O: Rapid Synthesis of Crystalline and Glassy Phosphates with NASICON-Type Chemistry

Preparation, characterization and conductivity studies of a Nasicon system Ag_3–2xTa_x Al_2–x (PO₄)₃ (x = 0.6–1.4)

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Ionic conductivities of crystalline and glassy Na4NbP3O12 and crystalline Na6Nb2P6O23

Cited by 8 publications

References 13 publications

Infrared and Raman spectroscopic studies of glasses with NASICON-type chemistry

Infrared and Raman spectroscopic studies of glasses with NASICON-type chemistry

High Microwave Susceptibility of NaH2PO4·2H2O: Rapid Synthesis of Crystalline and Glassy Phosphates with NASICON-Type Chemistry

Preparation, characterization and conductivity studies of a Nasicon system Ag3–2xTax Al2–x (PO4)3 (x = 0.6–1.4)

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Preparation, characterization and conductivity studies of a Nasicon system Ag_3–2xTa_x Al_2–x (PO₄)₃ (x = 0.6–1.4)