[Visitor (58.214.*.*)]answers [Chinese ]  Time :20200904  When the temperature is much higher than the Debye temperature, the heat capacity of the solid follows the classic law, that is, it conforms to the DulongPetit law, and is a constant that has nothing to do with the material constituting the solid, that is, Cv=3R (Cv is a constant Specific heat). Conversely, when the temperature is much lower than the Debye temperature, the heat capacity will follow the quantum law, and is proportional to the third power of the thermodynamic temperature. As the temperature approaches absolute zero, it quickly approaches zero. The latter conclusion is also called Debye law.
A parameter generated during the analysis of the solid specific heat theory according to the Debye hypothesis. Under Debye's hypothesis, the solid atomic vibration has a highest frequency (but not in fact), otherwise the solid energy statistics will tend to be infinite. After calculation, there is a direct relationship between Debye temperature and this highest frequency, namely:
θ/ω = (h/2π)/k
Among them, θ is the Debye temperature, ω is the highest vibration circle frequency, h is the Plank constant, and k is the Boltzmann constant. specifically,
ω^3 = 6π^2v^3N/V
Among them, v is the constant speed of sound, N is the number of solid primitive cells, and V is the volume of the solid.
The name is named after the American Dutch physicist Debye. Different solids have different Debye temperatures.
The higher the Debye temperature of a metal, the greater the force between atoms, the smaller the expansion coefficient, and the greater the Young's modulus. 
