Debye Temperature

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Debye temperature

[də′bī ′tem·prə·chər]
(solid-state physics)
The temperature θ arising in the computation of the Debye specific heat, defined by k θ = h ν, where k is the Boltzmann constant, h is Planck's constant, and ν is the Debye frequency. Also known as characteristic temperature.

Debye Temperature

 

a physical constant of matter that characterizes numerous properties of solids, such as specific heat, electric conductivity, thermal conductivity, broadening

Table 1
MetalθpSemiconductoθDDielectricθo
Hg...............60–90...............Sn (gray)...............212AgBr150
Pb...............94.5...............Ge...............366NaCI320
Na...............160...............Si...............658Diamond1,850
Ag...............225............... 
W...............270............... 
Cu...............339............... 
Fe...............467............... 
Be...............1,160............... 

of X-ray spectral lines, and elastic properties. The concept was first introduced by P. Debye in his theory of specific heat. The Debye temperature is defined by the equation

θD = h vD/k

where k is Boltzmann’s constant, h is Planck’s constant, and vD is the maximum frequency of the vibrations of a solid’s atoms. The Debye temperature indicates the approximate temperature limit below which quantum effects may be observed. At temperatures T ≫ θD the specific heat of a crystal consisting of atoms of one type at constant volume is Cr = 6 cal (°C. mole)-1, which agrees with Dulong and Petit’s law. At T ≪ θD the specific heat is proportional to (Γ/θp,)3 (the Debye T3 approximation).

Typical values of the Debye temperature for some substances are given in degrees Kelvin in Table 1.

References in periodicals archive ?
The Debye model of relaxation assumes that dipoles relax individually with no interaction between dipoles and with no inertia, but includes frictional forces.
In the limit of weak screening, the Debye model is recovered.
If [omega][tau] is eliminated in the Debye model, and the equations for [[epsilon]'.
For this equation the Debye model is obtained if [tau] (t) = [[tau].
This frequency dependence can manifest itself as the commonly observed frequency shift in the loss peak relative to the Debye model.
Thus, the Debye model correctly showed that the heat capacity is proportional to the [T.
The compensation can be done with analitical equations (in an Excel sheet) based on the wide band Debye model.
the Debye model [2], the Cole-Cole model [3], the Davidson-Cole model [4], and the Havriliak and Negami model [5, 6].
Finally, light scattering calculations are presented based on the Rayleigh Debye model to calculate the optical haze and transmission of these blends.
Initially, the dipoles relax partially and exponentially as in the Debye model with a generalized decay function,