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Bulk melting:
the objectives of the research

The main question, that is addressed in this part of our research, is how point defects influence on properties of the solid, and especially on its bulk melting temperature. To answer this question we investigated the various properties of a crystal of vanadium, containing point defects at different concentrations, as a function of temperature. The first task was to investigate the ``structure'' of point defects, i.e. to find all possible configurations of atoms around a self-interstitial, and choose the most stable one ( at low temperatures). The second objective was to find whether the various properties of the solid are affected to the same extent by self-interstitials and vacancies. Futhermore, to gain a better understanding of the rôle of the lattice structure a comparison was made between the results of our simulations (vanadium, bcc lattice) and the results obtained by A. Kanigel et. al [67] (copper, fcc lattice).

A. Kanigel et al. discovered that the bulk melting temperature of copper depends on the concentration of point defects (namely self-interstitials). Point defects expand the volume of the solid to a critical value at which the mechanical melting transition is triggered. According to A. Kanigel et. al the bulk melting transition is lowered by point defects! However, it was not clear if this mechanism of bulk melting is universal or it is specific for the fcc lattice of copper. Therefore, the primary aim of our investigation was to establish whether this mechanism is applicable for vanadium and point defects could lower the bulk melting temperature of this solid.


next up previous
Next: Investigation of the properties Up: Results: bulk melting transition Previous: Results: bulk melting transition
2003-01-15