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Equation of state, isobaric specific heat, and thermal expansion of solids with polyatomic basis in the Einstein‐Debye approximation
Author(s) -
Cankurtaran M.,
Askerov B. M.
Publication year - 1996
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.2221940207
Subject(s) - isobaric process , isochoric process , thermodynamics , heat capacity , thermal expansion , debye model , polyatomic ion , debye , debye function , equation of state , atmospheric temperature range , volume (thermodynamics) , einstein , chemistry , physics , debye length , condensed matter physics , plasma , ion , classical mechanics , quantum mechanics
A theoretical study of the thermodynamic properties in the Einstein‐Debye approximation is made for solids with polyatomic basis. Analytical expressions are derived for the equation of state, isobaric specific heat ( C p ), and linear thermal expansion coefficient (α P ). The temperature dependences of C p and α p are determined by four characteristic parameters of the solid: the Debye temperature θ D , the Einstein temperature θ E , and the Grüneisen parameters γ G acand γ G OPassociated with the volume dependences of θ D and θ E , respectively. It is shown that the difference C P − C V between the calculated isobaric and isochoric specific heat capacities is very small at low temperatures ( T ≪ θ D ) and increases markedly at higher temperatures. In the high‐temperature range ( T ≫ θ E ), C P is almost independent of temperature and is determined by a simple combination of the Grüneisen parameters γ G acand γ G OP . The results obtained for α P , in the low‐ and high‐temperature limits, are in accord with those found for the asymptotic behavior of C V with temperature.