Accession Number : AD0671064

Title :   AN INTERPRETATION OF THE INFRARED SPECTRA OF FUSED SILICA.

Descriptive Note : Technical rept.,

Corporate Author : ROCHESTER UNIV N Y DEPT OF CHEMICAL ENGINEERING

Personal Author(s) : Su,Gouq-Jen ; Bock,Jan

Report Date : MAY 1968

Pagination or Media Count : 56

Abstract : A vibrational analysis was performed for fused silica assuming the existence of short range order in the glassy network. This short range order was described by an average structural unit based on the model of alpha-quartz. The analysis consisted of using a group theoretical method and the Wilson FG matrix techniques to predict sixteen normal mode vibrational frequencies based on a diagonal force field. The most probable value of the three force constants, which were obtained by making the best fit between the calculated vibrational frequencies and the measured spectral values, is: K sub r = 480,000 dynes/cm Si-0 stretching; K sub alpha = 35,000 dynes/cm 0-Si-0 bending; K sub beta = 5,000 dynes/cm Si-0-Si bending. Although adherence to the selection rules was not observed, fifteen out of the sixteen predicted frequencies were within the experimental spectra of fused silica reported in the literature. (Author)

Descriptors :   (*SILICON DIOXIDE, INFRARED SPECTRA), MATRICES(MATHEMATICS), VIBRATION, FREQUENCY, BENDING, GLASS, CHEMICAL BONDS, KINETIC ENERGY, FORCE(MECHANICS)

Subject Categories : Ceramics, Refractories and Glass
      Atomic and Molecular Physics and Spectroscopy

Distribution Statement : APPROVED FOR PUBLIC RELEASE