Prigogine-Defay ratio

The Prigogine-Defay ratio is given by (Eq. 1 of ):

$\Pi ={\frac {1}{VT}}\left.{\frac {\Delta C_{p}\Delta k}{(\Delta \alpha )^{2}}}\right|_{T=T_{g}}$

where $V$ is the volume, $T$ is the temperature, $T_{g}$ is the temperature of the glass transition, $C_{p}$ is the isobaric heat capacity, $k$ is the compressibility and $\alpha$ is the thermal expansion coefficient.

References

Related reading

• R. M. Pick "The Prigogine–Defay ratio and the microscopic theory of supercooled liquids", Journal of Chemical Physics 129 124115 (2008)
• R. Casalini, R. F. Gamache, and C. M. Roland "Density-scaling and the Prigogine–Defay ratio in liquids", Journal of Chemical Physics 135 224501 (2011)