NIOSHTIC-2 Publications Search
Analysis of the Structure of a Glassy Carbon Using the Fourier Transform Technique.
The structure of a heat-treated ( 3000 deg c) glassy carbon produced from a polymer of furfural alcohol has been studied by the fourier inversion of scattering intensities obtained using agka1 radiation. Using cauchy's distribution, novel theoretical expressions have been developed for the fourier transforms that take into account the effects of distortion and defects in the lattice in addition to termination effects. The cosine transform of the (002) reflections showed that stacking of layers is extensive but faulty, mean spacing between faults being 21 a. The mean interlayer spacing was found to be 3.42+/-0.03 A, the value of 0.03 A representing the semi- quartile range of the mean interlayer spacing. A detailed analysis of the fourier transforms of the (hk) reflections revealed that the sample studied is made up of distorted hexagonal rings. The distortion is severe enough to make it very difficult, if not to prohibit, precise definition of the two-dimensional lattice. Three different lattices (two involving quinoidal rings) have been found to explain the observed transforms equally well. The transform yielded a mean defect-free distance in the layers of 86 a. Compared to 37 a indicated by the line-width of the (11) reflections, it is clear that distortion effects outweigh the defect or layer size effects in the observed profile of the (11) reflections.
Carbon, V. 11, PP. 127-138
Page last reviewed: May 5, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division