Debye Temperature

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 ?
Heat-conductivity of glasses at temperatures below the debye temperature.
B] almost coincide with the Debye temperature [[THETA].
Our computed acoustic Debye temperature, 1217 K, is about 20 % lower than the handbook calorimetric value.