Paper Title:

Micro-Raman Study on Structure Evolution of Graphite Exposed to Intense Thermal Shock Load

Periodical Advanced Materials Research (Volume 59)
Main Theme 1st International Conference On New Materials for Extreme Environment
Edited by Ch. Linsmeier and M. Reinelt
Pages 66-70
DOI 10.4028/www.scientific.net/AMR.59.66
Citation Takeshi Hirai et al., 2008, Advanced Materials Research, 59, 66
Online since December, 2008
Authors Takeshi Hirai, Jeremie Compan, Keisuke Niwase
Keywords Amorphous Carbon, Graphite, Raman Spectroscopy, Thermal Shock
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Abstract

A small area of a fine grain graphite block was exposed to intense thermal shock load at 9.6 GW/m2 and investigated by micro-Raman spectroscopy. Raman spectra of the loaded area show a reduction of the intensity ratio of D and G peaks in comparison with the one of unloaded graphite, indicating the ordering of graphitic structure even for as short as 5 ms. Raman spectra of the surrounding area, on the other hand, exhibited broad features of amorphous carbon, indicating a carbon deposits from the loaded area. The broad spectra showed a strong positional dependence, reflecting the temperature gradient of the block induced by the shock load. Fitting analysis of the Raman spectra clearly shows two linear relationships between the G-peak width (FWHMG) and the peak intensity ratio (ID / IG), corresponding to two steps of ordering process of the amorphous carbon deposits.