Arrangement mutuel des couches atomiques dans les carbones tendres partiellement graphités

✍ Scribed by Denise Tchoubar; Jacques Mering

• Publisher: Elsevier Science
• Year: 1973
• Tongue: English
• Weight: 794 KB
• Volume: 11
• Category: Article
• ISSN: 0008-6223
• DOI: 10.1016/0008-6223(73)90061-4

✦ Synopsis

The modulation functions C 'hk2 of the hk bands, such as h-k = 3m (m integer), were studied from X-ray diffraction diagrams produced by three specimens of partially graphitized carbons, corresponding to three different treatment temperatures. Let Pr be the degree of graphitization; the experimental results showed that for the specimens caracterized by P1 > 0.50, the modulation profiles are independent of the hk indexes. In this case they only depend on the frequency of the atomic layers, stacked with the translation A = *[Ii] a (u-parameter of the hexagonal cell), as in graphite. When P, < 0.50 we observe a fluctuation of A, isotropic in the layer plane. In this second case PI cannot be determined only by the G,,, modulation profile. The graphitized layers are slightly shifted with respect to each other. This shift is probably due to stresses exerted by the adjoining cristallites and it is vanishing when the layer diameters are increasing.