کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1517199 | 1511603 | 2008 | 7 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Isotopic heterogeneity in synthetic and natural silicon carbide Isotopic heterogeneity in synthetic and natural silicon carbide](/preview/png/1517199.png)
The distribution of both carbon and silicon isotopes in synthetic sublimation growth SiC wafers and in natural SiC grains was studied using secondary ion mass-spectrometry (SIMS). Significant variations in both isotopic ratios were observed which were broadly correlated with the crystalline perfection as documented by Raman microspectroscopy. Domains consisting of 15R (or with its admixture) are, on average, enriched in 12C isotope relative to 6H domains, and they also show larger scatter in their observed silicon isotope ratios. We ascribe such heterogeneity to fluctuations of Si/C ratio in the growth medium and it is possible to model the spatial extent of such fluctuations. For the natural SiC grains the isotopic data suggest that they grew under relatively stable conditions, although some of them show significant isotopic zoning.
Journal: Journal of Physics and Chemistry of Solids - Volume 69, Issue 10, October 2008, Pages 2492–2498