Gruneisen: thermodynamic parameter

The ratio aJCyPy multiphed by the reciprocal of the density of the substance (1/p) is called the Gruneisen thermodynamic parameter yoY-... 

More recently, Boness et al. (1986) calculated the band structure of both e-Fe and 7-Fe using the linear muffin-tin-orbital method under conditions corresponding to pressures ranging from 4 to 980 GPa. The results were used to, in turn, calculate electronic thermodynamic quantities such as the electronic specific heat and the electronic Gruneisen parameter, useful quantities with which to constrain models of the Earth s core. 

The coupling constant is of order dj. f2 p HTr. For a one-band model the Gruneisen parameter O is equivalent to the usual definition in terms of thermodynamic quantities (Wallace 1972),... 

For heavy fermions at low temperatures, > 50 dominates Q and C /T 1 J/mol dominates Cy so this correction can be quite large. For example, for UPts at lOK, where Q = 40, V = 42.4 cm /mol and C =3.25 J/mol K the correction is of order 12kbar, which is a large fraction of the total anomaly in the bulk modulus. (For mixed-valent compounds with To > lOOK this is less of a problem because the thermodynamic Gruneisen parameter is dominated by the phonon term, which is small.) Note that for heavy fermions, when Q Qe and C Cg, we have, by eqs. (8) and (13),... 

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