Combination Frequencies of the Infra-Red Bands of Quartz

Abstract

Many observers have studied the infra-red absorption bands of quartz and have found regions of intense absorption at 9/x, 12.5/*, 20yu and 26fx. These regions of absorption are assumed to be the fundamental frequencies of quartz. By combining these assumed fundamental frequencies six bands in the region from 3/j, to 9fx are accounted for. Also the writer has experimentally located two bands at 2.72/z and 3.18M which have not been previously observed. The frequencies of these two bands agree with two combinations of the fundamental frequencies. This gives a total of eleven absorption bands for the ordinary ray of quartz, extending from 2.72^ to 26^ whose frequencies agree, with only small differences, with the calculated values.

Vibrational spectra and dissociation of aqueous Na2SiO3 solutions

“…In table 2, we assign the observed IR vibrations of these two crystalline metasilicates to various Si-O vibrations based on their molecular geometry and published calculations for sodium silicate glasses [79][80][81] and gels [14,68,69,[82][83][84]. Pertinent data of certain crystalline silicates like quartz [14,70,71,85,94,95] and siliceous zeolites [72,73,96] are also referred in the table. A vast number of silica related spectroscopic study demonstrates that the stretching Si-O vibrations (m)appear at higher wavenumbers than the less energetic deformation vibrations (d) and asymmetric vibrations (m as , d as ) have usually also higher energies than their symmetric pairs (m s , d s ).…”

Preparation of hexagonal platy particles of nanoporous silica using hydrotalcite as morphology template

“…100 nm. All the absorption bands observed in the IR spectrum of L-C-C-HT (data not shown) [20] were ascribed to silicas [21][22][23]. The diffraction peaks ascribable to the mixed oxide of Mg and Al were not observed in the XRD pattern (Fig.…”

“…1f) showed two broad diffraction peaks at 0.21 and 0.15 nm ascribable to (400) and (440) reflections of a mixed oxide phase of magnesium and aluminum with the MgO type structure, which formed by the thermal decomposition of HT [33,34]. All the infrared absorption bands were ascribable to those of silica [21] and Mg-Al mixed oxides which contained remaining carbonate (1400, 860 and 650 cm −1 ) [28,35,36]. Thus, C-C-HT consisted of silica and mixed oxides of magnesium and aluminum.…”

“…The surface of the C-HT particle was smooth and homogeneous, and there are no cracks. In the infrared spectrum of C-HT (data not shown) [20], absorption bands due to Si-O stretching of silica (at around 1180 and 1080 cm −1 ) [21] and Si-O stretching of silanol groups (at around 960 cm −1 ) [21][22][23], in addition to those of HT (3450, 3020, 1350, 870, 780, 680 and 560 cm −1 ) have been observed. In the XRD patterns (Figs.…”

Using Reflectance Spectroscopy to Estimate the Orientation of Quartz Crystals in Rocks

“…These investigations revealed that quartz produces two distinct reflectance spectra in the mid-infrared (7-15 µm): one collected parallel to the optical axis (c-axis), and another collected perpendicular to the optical axis (a-axis) ( Fig. 1) (Coblentz 1906, Reinkober 1911, Plyler 1929, Saksena 1940, Simon & McMahon 1953, Spitzer & Kleinman 1961, Lyon & Burns 1963, Wald & Salisbury 1995, Wenrich & Christensen 1996. Building upon this early research, we collected reflectance spectra from quartz crystals using high spatial resolution spectrometers (i.e., 100 × 100 µm spot size) and used these spectra to derive orientation information from quartz crystals in a rock.…”