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30 m m

a). 30 m m. e). b). c). d).

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30 m m

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  1. a) 30 mm e) b) c) d) The arrangement of carbon (C) atoms differentiates a pencil lead from a pricey diamond. In this project we investigate how to control the arrangement of boron (B), carbon (C) , and nitrogen (N) atoms for the formation of frontier carbon materials: boron nitride (B-N), carbon nitride (C-N) and boron-carbon nitride (B-C-N) phases. Boron nitride nanotubes (BNNTs) are among the prospective materials for nanotechnlogy. They possess uniform electronic properties that are insensitive to their diameters and chiralities. This makes BNNTs very attractive for nanoelectronic and optoelectronic devices with predictable performance. Their band gaps are tuneable and can even be eliminated by transverse electric fields. This tunable property will trigger other innovative applications in the areas of nanoscale science and technology. However, high growth temperatures (>1100 ºC), low production yield, and impurities have prevented effective synthesis and applications of BNNTs in the past ten years. For the first time,  we show that BNNTs can be grown on substrates at 600 ºC. These BNNTs are grown vertically aligned on desired locations and patterns on the substrates (a). They can be used for applications without purification. Transmission electron microscopy indicates that the BNNTs are constructed of high-order tubular structures. A phase selective growth mechanism is demonstrated in this work. As shown, (b) low energy species will be coated as B-N films. Energetic species (c) will bounce away and prevent the coating of B-N films. Highly energetic species will react with the iron nanoparticles and form BNNTs (d & e). We anticipate that this mechanism can transform other thin film materials into nanostructures. This approach may also lead to the discovery of new nanophase materials.

  2. CAREER: Synthesis, Characterization and Discovery of Frontier Carbon Materials Yoke Khin Yap, Michigan Technological University,DMR-0447555 Education and Outreach to the younger generations and their families c d a b • In the past three years, more that 200 high school students and their families visited the laboratory during our campus open house (a & b). In each year, six seminars on nanotechnology were conducted in 3 hours. These visitors are form Michigan, Wisconsin, Illinois, Minnesota, etc. • This year, 4 Indian high school students have attended our Microsystems Summer Youth Program. • This year, 2 undergraduate students (Dave Price and Michael Gussert) conducted their 10-week Summer Research in the laboratory. A total of ten undergraduate students have been trained so far. • 2 groups of Michigan Tech undergraduate students (12 students /group) attended our Engineering Exploration (ENG1101) and laboratory tours (c) in Spring 2005. This exploration has been offered to 6 group of students at Michigan Tech. • A new graduate course (Ph5090/Ph5530: Selected topics in Nanotech) was initiated and opened for students across all fields at Michigan Tech. • This year, 22 physics freshmen (d) attended a seminar (PH 1160) on nanotechnology.

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