This dissertation can be divided into four parts. In part I (Chapter 2), the diffusion controlled growth of multiple compound phases is studied with the nonlinear Kirkendall effect included. This part analyzes the growth of N compound phases. The method of finding intrinsic diffusion coefficients from only the positions of interfaces is found for two layers. In addition, the asymptotic analysis valid for small concentration gradients is applied to the multi-foil method of measuring intrinsic diffusion coefficients and yields an analytic solution for the displacement curve.
A bounded solid film on a substrate can breakup from the edge into islands to reduce the surface energy. Part II (Chapter 3) studies the three-dimensional linear stability of a retracting film profile. An unstable mode of perturbation is found. The perturbed film profile is wavy along the film edge which can initiate the formation of fingers seen in experiments. The wavelength of the fastest growing perturbation agrees with the distance between two adjacent islands observed in experiments.
Part III (Chapter 4) studies the linear stability of square or triangular wires with azimuthal surface energy anisotropy. The growth rate of a normal mode is governed by an eigenvalue problem, which is solved numerically by a pseudospectral method. The fundamental and first modes, which correspond to varicose(sausage) and helical modes, are unstable for long wavelengths. The varicose mode has the highest growth rate for the range of parameters investigated. The maximum growth rate increases with anisotropy, implying that the anisotropy is destabilizing. An asymptotic solution is derived in the limit of zero anisotropy, and it agrees with the numerical solutions. The results obtained here for wires also apply to channels.
Part IV (Chapter 5) investigates Rayleighs instability of nano wires by classic molecular dynamic simulations. The melting point of nanowires with different radii is found by calculating the caloric curve and mean square displacement curve. Liquid and solid nano-wires with different radii are simulated. It shows that liquid wires breakup following Rayleighs instability criterion, whereas solid wires dont.
| Identifer | oai:union.ndltd.org:LSU/oai:etd.lsu.edu:etd-08302004-213631 |
| Date | 31 August 2004 |
| Creators | Kan, Wanxi |
| Contributors | Glenn Sinclair, Pratul K. Ajmera, Harris Wong, John M. Tyler, Andrzej K. Wojtanowicz |
| Publisher | LSU |
| Source Sets | Louisiana State University |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lsu.edu/docs/available/etd-08302004-213631/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached herein a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to LSU or its agents the non-exclusive license to archive and make accessible, under the conditions specified below and in appropriate University policies, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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