| MadSci Network: Chemistry |
Boundary conditions! If there were a simple answer, it would be that diamond is surface hydrogen-terminated. The real world is much more complex. The first definitive study was Bradford B. Pate, "The diamond surface: atomic and electronic structure" (252 pages), PhD thesis, Applied Physics, Stanford University (1984) Diamond was cleaved in ultra-hard vacuum and its surface atomic structure monitored by LEED (low energy electron diffraction). A clean diamond surface reverts to graphite a few atoms deep. In the presence of hydrogen radicals the clean surface is hydrogen capped and returns to being stable diamond. Hydrogen-capped diamond is hydrophobic and a p-type semiconductor for a few atoms deep. Diamonds in a slurry of pulverized kimberlite or lamproite (diamond ore, about 1-5 parts-per-million by weight) are remarkably selectively grabbed by corregated metal covered with grease. Melt off the grease, recover the diamonds. Diamond can also be oxygen terminated (various chemistries depending on the crystal face). That results in an insulating surface. pictures research calculations Diamond Res. Mater. 9 1171 (2000) J. Chem. Phys. 105 8977 (1996) J. Appl. Phys. 81 744 (1997) "Hydrogen chemistry on diamond surfaces: absorption, desorption, and vibrational spectroscopy" C. Su, H.-C. Cheng, J.-K. Wang, and J.-C. Lin "Handbook of Surfaces and Interfaces of Materials: Surface and Interface Analysis and Properties," Vol. 2, Chap. 8 (Academic Press, San Diego, 2001) -- Uncle Al gravitation test
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