Crystalline solid Debye crystal model

Debye temperature (6,) - In the Debye model of the heat capacity of a crystalline solid, 0 = hvjk, where h is Planck s constant, k is the Boltzmann constant, and is the maximum vibrational frequency the crystal can support. For T 0, the heat capacity is proportional to P. 

A common characteristic of all inteimetallic clathrates, independent of composition, is a relatively large, complex unit cell. For type 1 clathrates, the number of atoms per primitive unit cell, N, is 54. The effect of N on Kl for crystalline solids at high temperature was analyzed, using relatively simple models, by Slack [25]. A well-known inverse correlation between N and /Cl at the Debye temperature D for a crystal is described by the relation [25]... 

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