Debye Model EoSDebye-model Equation of State (EoS), appropriate for the phonon contribution in solids.
Energy density:
e = 3 n k T D3(x)
where n is the number density of atoms, D3(x) is the third Debye function, x=TD/T, and TD is the Debye temperature:
TD = [h cs / (2 k)] (6 n / π)1/3
cs being the sound speed in the material (value obtainable via the parameter, *.c_s).
With proper values of TD (in K), the atomic mass (in Da), and the mass density (as parameters), this block will provide the energy density (in J m-3) as a function of the input temperature (in K): e(T). The specific heat capacity, cv(T) (in J kg-1 K-1), is also calculated from the derivative wrt T:
cv = [e/T - 9 n k (B(x)-D3(x))] / ρ = n k [12 D3(x) - 9 B(x)] / ρ
where ρ is the mass density, B(x)=x/(exp(x)-1), and we have used xD'3(x)=3[B(x)-D3(x)] .
The default parameter values are those appropriate for copper.
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