Debye Temperature & Lattice Thermal Expansion

[Alexandros Lappas]

I wonder whether someone can help me with the following problem.   That is, I would like to know if there is a way to estimate the Debye temperature from crystal lattice thermal expansion.   I know that there is literature, and I have found the appropriate relations on how to calculate the Debye temperature from the temperature evolution of the isotropic thermal vibration of an atom (i.e. Debye-Waller factor is related to the mean-square thermal displacement of an atom) as determined by neutron or X-ray powder diffraction data.   However, I can not find out if there is a relation that pemits someone to get an estimate of the Debye temperature by fitting an appropriate function to the temperature evolution of the crystal lattice parameters (say from 1.8 to 300 K). My neutron data show clearly that the lattice thermal expansion is anisotropic and is not linear from 1.8 K all the way up to room temperature (actually it is linear only above roughly 100 K).   Many thanks in advance.   A. Lappas   ----------------------------------------------------------   Dr. Alexandros Lappas   Foundation for Research and Technology-Hellas (FORTH)   Institute of Electronic Structure and Laser (IESL)   P.O. Box 1527   Vassilika Vouton   711 10 Heraklion, Crete   GREECE   Tel: +30 81 391344, Fax: +30 81 391305  ----------------------------------------------------------