Infrared spectra and composition dependence investigations of the vitreous V2O5/P2O5 system

Infrared and Ultrasonic Investigations of Some [(MnO2)x-(P2O5)100?x] � 1 wt% Nd2O3 Glasses

“…The bands observed in this work at 1392 to 1377, 905 to 800 and 735 to 715 cm À1 could be attributed to the P¼O double bond [8,11], the stretching symmetric and the show absorption peaks between 260 and 655 cm À1 where this rare-earth oxide makes some contribution to the formation of some peaks in this range. Thus, the small fixed percentage of Nd 2 O 3 content in the glasses of this work led to the appearance of a small weak peak, independent of composition at 665-660 cm À1 .…”

“…The gradual addition of the metal-oxide to the vitreous P 2 O 5 matrix reveals in most cases an anomalous behavior, i.e., the appearance of three composition regions due to some structural changes. However, the second range of compositions was reported for different cases as: 18-50 mol% Co 3 O 4 [8], 22-53 mol% V 2 O 5 [11], 15-35 mol% MnO 2 [19] for binary phosphates. But it is 20-40 mol% MnO 2 in this work on manganese-phosphate glasses doped with 1 wt% Nd 2 O 3 .…”

“…Inspection of this figure reveals that all tested glasses show a great similarity in the shape of their absorption spectra which agrees with the results reported in [7,8], where the IR spectra of binary phosphate glasses are essentially the same. All observed absorption bands for worked glasses with their assignment based on the previous observations of phosphate glasses [7][8][9][10][11][12] are given in Table 1.…”

“…The experimental results of IR absorption spectra of some phosphate glasses were reviewed in [8], where it was found that the absorption frequencies in these spectra are mainly dependent on the nature of the anion rather than the positive ion. Other IR investigations showed that the phosphate tetrahedral unit dominates the structure of the glasses which contain transition metal oxides, e.g., CdO [9], ZnO [10], [8], V 2 O 5 [11] and TeO 2 -Bi 2 O 3 [12], and the increasing content of such oxides in the phosphate matrix can affect the positions of the obtained absorption bands of different modes of vibration, i.e., a shift toward higher number, indicating an increase in the number of tetrahedrally surrounded transition metal cation. It has also been reported [13][14][15] that glasses doped with Pr 6 O 11 show absorption bands between 260 and 655 cm À1 and it seems that this rare-earth oxide makes some contribution to the formation of new bands observed at 540 and 620 cm À1 .…”

Novel Calcium Phosphate Glass for Hard-Tissue Regeneration

“…Absorption spectra were collected using a Perkin-Elmer 983G quadruple grating spectrophotometer with scanning range from 4000 to 400 cm -1 after mixing the samples with KBr powder and pressing at 10000 psi in a vacuum. Absorption spectrum with Ca/P of 0.4 showed broad peaks, which is a typical pattern in amorphous glass materials [8][9][10] as pre- Another peak around 1100 cm -1 is due to F-O in phosphate [8] originating from CaF 2 as a precursor. The IR peak which changed from broad to sharp shape with increasing Ca/P ratio indicates increasing crystallinity in accordance with the XRD results shown in Fig.…”