Accession Number : ADA191730

Title :   Effect of Uniaxial Stress on the Raman Spectra of Graphite Fibers.

Descriptive Note : Rept. for 1 Sep 86-31 Aug 87,

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE

Personal Author(s) : Sakata, H ; Dresselhaus, G ; Dresselhaus, M S ; Endo, M

PDF Url : ADA191730

Report Date : 30 Oct 1987

Pagination or Media Count : 16

Abstract : Measurements of the effect of uniaxial stress on the frequency of the zone center optical phonons in heat-treated benzene-derived graphite fibers have been performed using first-order Raman scattering. Application of uniaxial stress along the fiber axis was found to cause polarization-dependent splittings and shifts of the Raman peaks of the zone center doubly degenerate optical phonons. From these observed splittings and shifts, experimental values for the phenomenological coefficients which describe the changes in the elastic constant of these phonons with strain were determined. It is concluded that Raman spectroscopy can be used to characterize the local stress or strain conditions of graphite fibers nondestructively. Keywords: Effect of uniaxial stress, Raman spectra of carbon fibers, Raman microprobe spectroscopy, Single carbon fibers.

Descriptors :   *CARBON FIBERS, *PHONONS, *RAMAN SPECTRA, *STRESS ANALYSIS, ELASTIC PROPERTIES, FIBERS, GRAPHITE, LIGHT SCATTERING, OPTICS, POLARIZATION, RAMAN SPECTROSCOPY, STRESSES, NONDESTRUCTIVE TESTING, JAPAN

Subject Categories : Refractory Fibers

Distribution Statement : APPROVED FOR PUBLIC RELEASE