Spectroscopic Estimation of Geometrical Structure Elucidation in Natural SiO<SUB>2</SUB> Crystal

Abstract

This study demonstrate for the first time the geometrical structure change relationship of natural quartz crystal structures with its purity through infrared spectroscopy. Systemetatic investigations of geometrical structure changes of the quartz crystals have been carried out in mid infrared region 500-1000 cm -1 based on the assignment of infrared bands of the structural group SiO 4 tetrahedra. The compositional and structural studies were carried out at room temperature by using X-ray fluorescence (XRF) and Fourier transform infrared (FTIR) spectroscopic techniques. The variation of geometrical structure of quartz crystals has been ascertained by comparing the infrared and X-ray fluorescence results. Results depict the variation of crystal size and shift of characteristic peak positions of the studied samples are depends on its purity. The infrared investigation is found to be good for structure elucidation and changes of geometrical crystal structures of the natural quartz crystals.

Physical and chemical properties of dust in the Pre-Aral region of Uzbekistan

“…The peak at 694 cm −1 is close to that at 695 cm −1 , which according to Ref. (Saikia 2014) belongs to Si-O symmetrical bending vibration. It arises due to the octahedral site symmetry and is the indicator of crystalline nature of quartz.…”

Raman and FTIR Spectroscopic Evaluation of Clay Minerals and Estimation of Metal Contaminations in Natural Deposition of Surface Sediments from Brahmaputra River

“…The Si-O symmetrical bending vibrational peak at 695 cm -1 of the octahedral site symmetry is unique to the crystalline materials. All infrared spectra reveals peak at this range, therefore crystalline quartz particles present in the observed samples [28]- [30]. The infrared spectra reveals bands at 1014 -1018 cm −1 are close to the SiO deformation band obtained for kaolinite.…”

“…The observed doublet at 914 and 936 cm −l can also be recognized by kaolinite. The infrared peak corresponding to the range 536 -541 cm −1 is arising due to Si-O asymmetrical bending vibrations and 641 -649 cm −1 is arising due to Al-O-coordination vibrations and these peaks are indicative to the presence of orthoclase feldspar [27] [28]. In the infrared spectra, the observed band at 777 -780 cm -1 is arises due to Si-O symmetrical stretching vibration (v1), the band at 693 -696 cm −1 is arise due to Si-O symmetrical bending vibration (v2), and the peaks around 468 cm -1 is arise due to Si-O asymmetrical bending vibration (v4) are indicative to quartz.…”

Mechanical Activation of Construction and Demolition Waste in Order to Improve Its Pozzolanic Reactivity

“…The FTIR spectra can be characterized by a broad band between 3611 and 2813 cm –1 centered at 3352 cm –1 related to (O–H) stretching and a smaller band at 1631 cm –1 (O–H bending mode), both of which correspond to water (structural and weakly bound water). The band at a wavenumber of about 460 cm –1 and about 1000 cm –1 are attributed to the asymmetric stretching of T–O (Al–O and Si–O) bonds of the aluminosilicate structure originated from the presence of feldspars and muscovite, and remnants of the binder gel band appear at 1000 cm –1 , assigned to the asymmetric stretching mode of the C–S–H structure formed in OPC meaning Al–O and Si–O bonds of aluminosilicate structure. The carbonate in the system is characterized by absorption at 1411 cm –1 , which indicates the presence of carbonates (calcite and dolomite) originated from the binder .…”