An Equation of State of Corundum Based on Planck–Einstein Functions

• Published in: Russian Journal of Physical Chemistry A Vol. 97; no. 4; pp. 565 - 572
• Main Authors: Perevoshchikov, A. V., Kovalenko, N. A., Uspenskaya, I. A.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01-04-2023; Springer Nature B.V
• Subjects: Aluminum oxide; Chemical Thermodynamics and Thermochemistry; Chemistry; Chemistry and Materials Science; Corundum; Enthalpy; Equations of state; Modulus of elasticity; Physical Chemistry; Thermal expansion; isothermal compression; isobaric heat capacity; corundum; equation of state; Planck–Einstein functions; thermal expansion
• ISSN: 0036-0244; 1531-863X
• DOI: 10.1134/S0036024423040222

The possibility of constructing the equation of state of a crystalline substance based on a linear combination of the Planck–Einstein functions is shown using the example of corundum α-Al
2
O
3
. Two versions of the corundum equation of state are obtained on the basis of functions
F
(
V
,
T
) and
G
(
P
,
T
) as a result of the self-consistency of the heat capacity values, the enthalpy increment,
PVT
data, the coefficient of thermal expansion, and the adiabatic modulus of elasticity. Both equations provide an acceptable description of the above properties in a wide range of variables (up to a pressure of 165 GPa and a temperature of 2250 K).