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Indian Journal of Pure & Applied Physics (IJPAP) >
IJPAP Vol.43 [2005] >
IJPAP Vol.43(09) [September 2005] >
| Title: | Temperature dependence of lattice energy of fluorite type AB2 crystals, alkaline earth oxides and heavy metal halides – Evaluation from sound velocity data |
| Authors: | Subrahmanyam, M
Rajagopal, E
Murthy, N Manohara |
| Keywords: | Lattice energy
Kudriavtsev's theory
Elastic constants
Ultrasonic velocity |
| Issue Date: | Sep-2005 |
| Publisher: | CSIR |
| IPC Code: | C08F2/56 |
| Abstract: | Lattice energies of CaF2, SrF2,
BaF2, CdF2, EuF2, MgO, SrCl, AgCl and TlBr at
different temperatures have been evaluated making use of single crystal elastic
constant data and employing Kudriavtsev’s theory which relates the lattice
energy of the crystal, U, with mean
sound velocity, um, in the
crystal. The lattice energies of both MgO and SrO decrease with increase in
temperature and the variations are parabolic and similar. The lattice energies
of AgCl and TlBr vary with temperature parabolically up to 80 K and thereafter
linearly up to 300 K. The results are explained in terms of the structure of
the crystals, mutual interaction of the ions and anharmonic effects associated
with as a function of temperature. |
| Page(s): | 660-663 |
| ISSN: | 0975-1041 (Online); 0019-5596 (Print) |
| Source: | IJPAP Vol.43(09) [September 2005]
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