MSc., Faculty of Science, University of the Witwatersrand, 2011 / Materials are modeled by the ab-initio plane wave pseudopotential methods using density
functional theory. In this work, we are seeking new ultrahard with enhanced elastic and
mechanical properties, thermal stability as well as hardness which might be of advantage
over known traditional materials (diamond and cubic boron nitride). Structural, elastic and
electronic properties of the advanced metal nitrides M2N3 and their ternary phases were
investigated using both the local density approximation (LDA) and the generalized gradient
approximation (GGA). The relative stability of the ternary phases with respect to their
constituent mixtures is computed. Results obtained are compared with the available experimental
and theoretical data. To gain more information concerning the elastic properties of
these hypothetical materials, we also computed the charge densities of the binary and ternary
phases. From these calculations suggestions are made as to how the elastic properties vary
from those of known hard materials.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:wits/oai:wiredspace.wits.ac.za:10539/10539 |
| Date | 12 October 2011 |
| Creators | Orisakwe, Esther Nkiruka |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | application/pdf |
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