tailieunhanh - Báo cáo hóa học: " Iron Oxide Nanoparticles Employed as Seeds for the Induction of Microcrystalline Diamond Synthesis"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Iron Oxide Nanoparticles Employed as Seeds for the Induction of Microcrystalline Diamond Synthesis | Nanoscale Res Lett 2008 3 65-70 DOI S11671-008-9117-5 NANO EXPRESS Iron Oxide Nanoparticles Employed as Seeds for the Induction of Microcrystalline Diamond Synthesis Kishore Uppireddi Oscar Resto Brad R. Weiner Gerardo Morell Received 3 October 2007 Accepted 9 January 2008 Published online 24 January 2008 To the authors 2008 Abstract Iron nanoparticles were employed to induce the synthesis of diamond on molybdenum silicon and quartz substrates. Diamond films were grown using conventional conditions for diamond synthesis by hot filament chemical vapor deposition except that dispersed iron oxide nanoparticles replaced the seeding. X-ray diffraction visible and ultraviolet Raman Spectroscopy energy-filtered transmission electron microscopy electron energy-loss spectroscopy and X-ray photoelectron spectroscopy XPS were employed to study the carbon bonding nature of the films and to analyze the carbon clustering around the seed nanoparticles leading to diamond synthesis. The results indicate that iron oxide nanoparticles lose the O atoms becoming thus active C traps that induce the formation of a dense region of trigonally and tetrahedrally bonded carbon around them with the ensuing precipitation of diamondtype bonds that develop into microcrystalline diamond films under chemical vapor deposition conditions. This approach to diamond induction can be combined with dip pen nanolithography for the selective deposition of diamond and diamond patterning while avoiding surface damage associated to diamond-seeding methods. K. Uppireddi El B. R. Weiner G. Morell Institute for Functional Nanomaterials University of Puerto Rico San Juan PR 00931 USA e-mail uppireddi@ K. Uppireddi O. Resto G. Morell Department of Physics University of Puerto Rico San Juan PR 00931 USA B. R. Weiner Department of Chemistry University of Puerto Rico San Juan PR 00931 USA Keywords Iron nanoparticle Diamond EFTEM EELS Dip pen nanolithography Introduction Many challenges remain opening