Infrared (IR) = 2 / =2/*

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()()( ):():He,Ne,Ar,Kr,Xe. (homonuclear Diatomics): H2 ,N2 ,O2 ,F2 ,Cl2 . H2S*

Diffuse Reflection () --Specular Absorption Reflection ()Grazing Angle Reflectance -- A Total Reflectance (ATR ) -- 0.2 - 6 um()*

:KBr, KCl, NaCl, KI, CsI PE powder : a) b) KBr c) d) 13mmdie e) 15ton f) 13mm

KBr ()*

FTIRIR sourceLaser*

4400.020001000450.0cm-14400.020001000450.00.320406080.8cm-1%T RatioBackground Sample *

IR spectra of RO-ZnO-B2O3 (RO= MgO,CaO, SrO and BaO) glassesNo peak at 806cm-1 , no boroxol ringBO3 asymmetric stretching vibrations of B-O and B-O bond. These bands have become broad in present glasses in the order MgO < CaO < SrO < BaO. 1200-1400 cm-1 is =B-O-B linkage. BZASZBCZBMZBH2O, OH BO4 BO3 bending vibration of borate segments *

IR spectra of RO-PbO-B2O3 (RO= MgO,CaO, SrO and BaO) glassesBO4 groupsthe peaks around 1374-1407cm-1 which are overlapping on vibration of BO3 units might reveal the existence of PbO3 and PbO4 pyramids.*

Al2O3/CaO=0.5CaO=20mol%SiO2=60mol%IR spectra of CaO-Al2O3-SiO2 glasses*

Vibration of O in Al-O-Si or Si-O-Si :475cm-1. The shift of the band to lower frequencies with the addition of alumina can be explained by an increase in the number of Si-O-A1 bonds, which have a smaller force constant.

2. AlO4 tetrahedra : 710cm-1.

3. Si-O bending and A1-O stretching, with the aluminum ions in four-fold coordination:750~800cm-1.

4. The bands observed in the 850 to 1300 cm-I region are due to the effect of calcium ions and aluminum ions on the Si-O bonds. The band of shifts from higher frequencies to about 880 cm-1 as the alumina content was increased. This shift was attributed to the presence of Si(OA1)3 and Si(OA1)4, i.e., silicon-oxygen tetrahedra with three and with four corners shared with aluminum-oxygen polyhedra, respectively. The sub-region of 1050~ 1100 cm-1 represents the vibration of the Si(OA1/Ca) group, i.e., the stretching vibration of the silicon-oxygen bond of the [SiO4] tetrahedra with one corner shared with an aluminum or calcium polyhedron. The shoulder observed on the 1100 cm-1 band, in the spectra of glasses with a silica content higher than 60 mol%, is probably a vibration of SiO4 with four bridging oxygens. The low energy part is likely due to Si(OA1/Ca) 3 and Si(OA1/Ca)4. This latter band was said to be due to [SiO4] tetrahedra with three or four non-bridging oxygens.

5. The aluminum ions were four-fold coordinated in CaO-Al2O3-SiO2 glasses. No six-coordinated aluminum present in CaO-Al2O3-SiO2 glasses. This is different from the structure of Na2O-Al2O3-SiO2 glasses. [AlO6] polyhedron presents in Na2O-Al2O3-SiO2 glasses as Al2O3/Na2O > 1. In CaO-Al2O3-SiO2 glasses, the excess aluminum not included in the tetrahedral aluminosilicate network forms neutral species, triclusters, i.e. three-coordinated oxygen. *

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RamanAbsorbedTransmittedReflectedScatteredIncident light l0l0l0l0l l0l l0ElasticInelasticRayleigh scatteringRaman scattering*

mind=aEa: poalrizability*

Raman L1 10m L2 M1 M2 *

Raman

(CCl4)Raman*

The 440 cm-1 band results from symmetric motion of the bridging oxygen relative to the silicon atoms in the three-dimensional network structure (ns(Si-O-Si)). Although the 440 cm-1 band has been assigned to a transverse optic (TO) mode and the 492 cm-1 band to a longitudinal optic (LO) mode, the ns (Si-O-Si) mode is infrared inactive. The weak band at 606 cm-1 is attributed to defect structures in the silica network. The broad envelope located near 800 cm-1 is associated with the network structure of the SiO2 glass, as its intensity drops with depolymerization of the glass. Oxygen isotopic substitution data for SiO2 glass indicate that the 800 cm-1 feature results primarily from silicon motion. Two broad, weak, and depolarized bands at 1060 cm -1 and 1190 cm-1 are probably due to the antisymmetric Si-O-Si stretching mode (nas(Si-O-Si)) in which the bridging oxygen atom moves parallel to the Si-Si axis. Raman spectra of alkali silica glasses (J. of Non-Crysta. Solids 58 (1983) 323-352)

Raman spectrum (Iand I ) of silica glass*

Raman spectra of alkali silicate glasses440 cm-1 (ns(Si-O-Si)) TO mode, 492 cm-1 LO mode, 606 cm-1 defect structures in the silica network. 800 cm-1 network structure of the SiO2 glass, as its intensity drops with depolymerization of the glass. Oxygen isotopic substitution data for SiO2 glass indicate that the 800 cm-1 feature results primarily from silicon motion. 1060 cm -1 and 1190 cm-1 are TO and LO mode of nas(Si-O-Si).*

500cm-1 pentaborate, tetraborate and diborate groups.550 cm-1 isolated diborate groups.660cm-1 pentaborate groups.806cm-1 Boroxol ring.770cm-1 BO4 unit. 950 cm-1 pentaborate and tetraborate groups. The shift of the 950cm-1 to a lower value (925cm-1) is attributed to the linking of pentaborate and tetraborate groups to the orthoborate type of structure. 840 and 1210 cm-1 symmetric stretching of the B-O-B bridges and to the stretching of the terminal B-O- bonds, respectively, in B2O5-anions. (pyroborate)1300~1500cm-1 stretching of B-O- bonds.Raman spectra of xLi2O-(1-x)B2O3 glasses (J. Phys. Chem. Solids, 54 (1993) 621)*

Boroxol unit; B2O3(b) pentaborate unit;Li2O-5B2O3(c) triborate unit; Li2O-3B2O3(d) orthoborate unit; 3Li2O-B2O3(e) metaborate unit; Li2O-B2O3(f) pyroborate unit; 2Li2O-B2O3(g) diborate unit; Li2O-2B2O3(h) loose BO4. Solid circlea represent boron atoms andopen circles oxygen atom. An open circle with a negative sign indicates a non-bridging oxygen.The schematic representation of different borate arrangements. *

Low frequency Raman spectra in xLi2O-(1-x)B2O3 glasses The low frequency part of the Raman spectra of glasses is dominated by the so-called boson peak. It represents the extent of short-range ordering where a phonon can propagate with no damping. the SCR can be estimated simply from the relation2s = vtpc /wwhere vt is the transverse acoustic waves, w is the peak position of the boson peak. The short-range ordering in lithium borate glasses as shown in figure below does not exceed the dimension of one six-membered ring (8 ). The formation of BO4 units which results from the addition of Li2O to B2O3 frustrates the preferential ordering of the BO3 triangles and therefore reduces the SCR to 4.2 (at x = 0.50) in the lithium borate glasses.135 cm-1 band in lithium borate glasses may be attributed to the torsion modes of BO3 and BO4 units.*