Thermodynamic properties of the alkali metals at high pressures and high temperatures
The melting temperatures of Li, Na, K, Rb, and Cs versus pressure were measured to 32 kbar in a piston cylinder apparatus with hydrostatic pressure medium and in situ pressure measurements. The accuracies in pressure and temperature are +/- 0.4% and +/- 0.25/sup 0/C, respectively. Substantial deviation from measurements using solid, non-hydrostatic pressure media is observed. The adiabat, (deltaT/deltaP)/sub s/, was measured to 32 kbar and 400/sup 0/C by adiabatic compression. Ln (deltaT/deltaP)/sub s/ is a linear function of volume with good consistency in the slopes. (deltaT/deltaP)/sub s/ changes insignificantly at the liquid-solid phase transitions. The Grueneisen parameters, calculated from ..gamma.. = B/sub s//T (deltaT/deltaP)/sub s/, decreases with pressure and temperature. B/sub s/ is the adiabatic bulk modulus. The ..gamma..-volume curves show strong curvature and ..gamma.. tends to become volume independent at compressions of about 30%. ..gamma.. increases by several percent at the liquid-solid transition.
- Research Organization:
- Univ. of California, Los Angeles
- OSTI ID:
- 5771390
- Report Number(s):
- CONF-830763-Pt.2
- Journal Information:
- Mater. Res. Soc. Symp. Proc.; (United States), Journal Name: Mater. Res. Soc. Symp. Proc.; (United States) Vol. 22; ISSN MRSPD
- Country of Publication:
- United States
- Language:
- English
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