Phases and Microstructures of Carbon-Implanted Niobium

摘要

Polycrystalline niobium was implanted with 200, 100, and 50 keV carbon ions to create a uniform distribution of carbon over a thickness of about 0.25 mu m. Samples implanted with calculated carbon content of 0.6, 1.9, 5.8, and 16 atomic percent were prepared, and the uniformity of the carbon distribution with depth was confirmed by Auger electron spectroscopy analysis. Glancing-angle x-ray diffraction analysis and transmission electron microscopy were used to characterize the phases and microstructures formed. The results indicated that no detectable second phases were present except on the surfaces where an amorphous phase and many particles were formed from contamination. Despite the low equilibrium solubility limit of carbon in Nb, we have created metastable solid solutions of Nb and C with carbon contents as high as 16 at.%. 7 refs., 5 figs., 1 tab. (ERA citation 14:011348)