کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5424049 | 1395812 | 2009 | 10 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Surface morphology and composition of c-, a- and m-sapphire surfaces in O2 and H2 environments
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
This paper reports that monitoring the composition of the c(0Â 0Â 0Â 1), a(11-20) and m(10-10) sapphire surfaces is essential for a proper interpretation of the surface morphologies obtained after annealing at 1253 and 1473Â K in ArH2 or ArO2 atmospheres. Our experimental investigations, which have used Auger electron spectroscopy (AES) and atomic force microscopy (AFM) on the surfaces of 99.99% pure sapphire wafers, have led to the following original conclusions: (i) Calcium segregates at the c-surface of sapphire both under ArO2 and ArH2. (ii) Potassium adsorption enhances the kinetics of step-bunching on the c-surface under ArO2. (iii) The step edges on the a-surface may develop a comb-like morphology made of parallel strips along the [10-10] direction. (iv) At 1253Â K, clean m-surfaces may be stable. (v) Under ArH2, alumina surface diffusion is much slower than under ArO2 for all surface orientations, the surface concentration of impurities is low, and the Al-O ratio of the AES signals at the surface is significantly larger.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Surface Science - Volume 603, Issue 17, 1 September 2009, Pages 2688-2697
Journal: Surface Science - Volume 603, Issue 17, 1 September 2009, Pages 2688-2697
نویسندگان
Stefano Curiotto, Dominique Chatain,