کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
702604 891103 2011 5 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Investigation of the initial growth of ultrananocrystalline diamond films by multiwavelength Raman spectroscopy
موضوعات مرتبط
مهندسی و علوم پایه سایر رشته های مهندسی مهندسی برق و الکترونیک
پیش نمایش صفحه اول مقاله
Investigation of the initial growth of ultrananocrystalline diamond films by multiwavelength Raman spectroscopy
چکیده انگلیسی

The initial growth phase of ultrananocrystalline diamond/amorphous carbon nanocomposite films (UNCD/a-C) has been investigated by scanning electron microscopy, atomic force microscopy and especially Raman spectroscopy. As due to resonance effects Raman spectra of carbon materials strongly depend on the excitation wavelength, a multiwavelength analysis has been performed with λexc ranging from the UV region (325 nm) over the visible range (488 and 514 nm) to the IR region (785 nm). In addition, a set of measurements has been performed with a confocal Raman microscope, i.e. depth resolved, with a wavelength of 532 nm. The samples investigated were deposited with constant parameters, the deposition time being the only parameter varied, resulting in film thicknesses from 100 to 500 nm. It turned out that the diamond fraction and also the grain boundary material do not vary during that stage whereas there are slight but distinct changes of the nature of the amorphous matrix which reflect, among others, in a shift of the graphite-related G band to higher wavenumbers and in an increase of the ratio of D and G bands with increasing film thickness. These changes are discussed in terms of the above mentioned resonance effects; the major changes are a transition of hydrogen containing sp2 chains to hydrogen-free condensed sp2 rings when the material is no longer in the surface region of the films but becomes incorporated within the film bulk.

Research Highlights
► Investigation of the first stages of UNCD growth.
► Multiwavelength Raman spectroscopy.
► Confocal Raman spectroscopy.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Diamond and Related Materials - Volume 20, Issue 7, July 2011, Pages 1076–1080
نویسندگان
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