Experimental data on the structural phase changes in zirconia are summarized. The computational
techniques of molecular dynamics are reviewed and equations of motion are formulated
which allow the study of phase changes as a function of temperature and pressure.
The molecular dynamics program NPT which was written for this purpose is described.
This program performs numerical integration of the classical equations of motions in atomistic
simulations which allow a varying cell size and shape. The simulations produce time averages
which are related to thermodynamic ensemble averages.
Routines used to calculated the interatomic forces are implemented for potentials which
vary as the inverse power of the separation distance between atoms. Calculation of Coulomb
forces is done with the Ewald method and with a multipole method. The two methods are shown
to be analytically equivalent and the precision and speed of the two routines are compared.
Results generated by the program NPT are presented for energy minimization of crystal
structures and for dynamic simulations.
A number of different minimum-energy structures for soft-sphere potentials are found. Simulations
are performed for several soft-sphere structures and dynamic properties are established.
Structural phases changes are observed in two cases.
A potential derived from ab initio calculations for monoclinic zirconia is tested. / Graduation date: 1994
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/36176 |
| Date | 03 September 1993 |
| Creators | Love, Michael J. |
| Contributors | Jansen, H. J. F. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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