PHYS 419 |
| Electron emitting materials are one of the frontiers of material science because of their important applications in electron microscopes, e-beam lithography, flat panel field-emission displays and high power micro wave amplifiers. Recent materials research has suggested that the development of high aspect ratio nanostructures from low work function refractory materials can enhance the emission properties of current devices with much lower operating voltage and hence higher efficiency. While low work function single-crystalline LaB6, CeB6, PrB6 nanowires have been reported to have good field emission properties, the NdB6 material, which has a much lower work function (1.6eV) than that of LaB6 (2.6eV), has not yet been explored. Herein we report the synthesis of single-crystalline NdB6 nanowires and nanoobelisks by catalyst-assisted chemical vapor deposition via a vapor-liquid-solid growth mechanism. The reactions were performed with neodymium trichloride and decaborane gas mixed with argon. The morphology of the nanostructures was studied by scanning electron microscopy and high resolution transmission electron microscopy. Selected area electron diffraction patterns indicate that these nanostructures are single-crystalline cubic materials with growth along the [100] direction. The effect of shapes of different NdB6 nanostructures on their field emission properties will also be discussed. |
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PHYS Poster Session - Nanostructured Materials and Nanophotonics
7:30 PM-10:00 PM, Wednesday, April 9, 2008 Morial Convention Center -- Hall A, Poster
Sci-Mix
Division of Physical Chemistry |