The vibrational spectra of α-MoPO5 and α-NbPO5

Glass-forming ability and structure of ZnO–MoO3–P2O5 glasses

“…In the structure of all crystalline compounds described in the P 2 O 5 -MoO 3 system, i.e. MoO 2 (PO 3 ) 2 [29], (MoO 2 ) 2 P 2 O 7 [30], MoOPO 4 [31] and Mo 2 O 2 P 4 O 13 [32] molybdenum atoms form MoO 6 octahedra regardless of the molybdenum valence.…”

“…Crystallization temperature was taken as the onset of the crystallization peak. 31 P MAS NMR spectra were measured using a 9.4 T NMR spectrometer (Larmor frequency 162.3) with a 4 mm probe. The spinning speed was 12.5 kHz.…”

Enhanced Raman scattering in thermally poled sodium-niobium borophosphate glasses

“…In this case, the symmetric stretching of NbO 6 octahedra occurs at around 800 cm −1 . 16 Also, bands between 650 and 750 cm −1 appear in niobate oxides possessing block structures with distorted NbO 6 octahedral. For example, in crystalline phases H-Nb 2 O 5 and ͑P or V͒Nb 9 O 25 the corner-sharing NbO 6 octahedra, which are slightly distorted with Nb-O bonds ranging from 1.9 to 2 Å, exhibit their symmetric stretching in the range of 600-650cm −1 .…”

Negative thermal expansion properties in tetragonal NbPO5 from the first principles studies

“…There are forty two vibrational modes in NbPO 5 , we only show in Fig. 3 the diagrams of the eigenvector representations 22 of some low energy zone-center optical phonon modes which could contribute most to the NTE.…”

“…21 Stranford et al have reported the Infrared and Raman spectra of β-and α-NbPO 5 and made the band assignments by using normal coordinate analysis. 22,23 But up to now, there have no theoretical analysis of the NTE behavior systematically in tetragonal NbPO 5. The vibrational property and Grüneisen parameter are important and useful to illustrate the mechanism of NTE, but have not been reported yet in literatures.…”