کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
702279 | 891088 | 2008 | 5 صفحه PDF | دانلود رایگان |
To have insight to the atomistic process of graphitic ordering in tetrahedral amorphous carbon films which is induced by irradiation of high-energy electrons, the role of temperature in the graphitization was experimentally studied. The change of electron diffraction patterns before and after irradiation at room temperature indicated graphitic ordering, but irradiation at − 170 °C resulted in disordering. Systematic measurements of the temporal evolution of electron energy loss spectra with irradiation at various elevated temperatures and data analysis based on the Johnson–Mehl–Avrami model yielded the activation energy for electron-stimulated ordering of as small as ∼ 0.09 ± 0.01 eV. The most plausible model to account for all the experimental facts is the dissociative diffusion that is triggered by the electron-stimulated displacement of carbon atoms at the initial sites.
Journal: Diamond and Related Materials - Volume 17, Issue 2, February 2008, Pages 137–141