Theory of the elastic constants of the rare gas solids.
Paik, D. S. (1978) Theory of the elastic constants of the rare gas solids. Doctoral thesis, University of Surrey (United Kingdom)..

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Abstract
Some general results for thermoelastic quantities are derived by considering a solid in different states of strained reference frames. It is shown that simple relationships hold between the nth order and the volume derivatives of (n1)th order elastic constants. Explicit expressions for these results are obtained for a cubic solid. The contribution to thermoelastic properties of the inert gas solids Ne, A, Kr and Xe for longrange threebody forces of the form given by Axilrod and Teller are calculated. The second order elastic constants C[ij] and the third order elastic constants C[ijk] are calculated at the absolute zero assuming only twobody forces. The approach employed here was not the standard lattice dynamical methods. Instead, an Einstein model modified for anisotropic effects and including correlation as a perturbation was used. This model was found to be more flexible than the standard lattice dynamical approach. Where possible comparision with standard lattice dynamical methods was made. It is shown that although both, the threebody forces and the twobody zeropoint effects violate the Cauchy relations they do so in opposite sense. In the case of some of the it is found that contributions due to threebody forces and twobody zeropoint effects are often larger than the classical twobody contributions and differing in sign. The calculations of the C[ijk] have further shown that in a certain instance it is possible to distinguish between the contributions of the 3body forces and the twobody zeropoint effect, which is not possible in the case of the C[ij] A method is presented to calculate in a simple manner the contribution of the zeropoint energy and the freeenergy at finite teperatures to the elastic constants. In the case of the C[ij] where comparision with refined lattice dynamical method are available, good agreement is found. The method also enabled us to assess the many particle correlation effects.
Item Type:  Thesis (Doctoral)  

Divisions :  Theses  
Authors : 


Date :  1978  
Contributors : 


Additional Information :  Thesis (Ph.D.)University of Surrey (United Kingdom), 1978.  
Depositing User :  EPrints Services  
Date Deposited :  22 Jun 2018 14:25  
Last Modified :  06 Nov 2018 16:53  
URI:  http://epubs.surrey.ac.uk/id/eprint/847889 
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