Abstract
The free energy, entropy and enthalpy of sodium feldspar in thermal equilibrium and in metastable states are derived from investigations of the heat capacities of albite, analbite, ordered and disordered Or31. The lattice strains of all stable and metastable states are calculated from the two-order parameter theory published in the preceding paper. This approach also allows one to distinguish between the influence of Al, Si order and of the displacive lattice distortion on the thermodynamic behaviour of albite. The thermal cross-over between high albite and low albite is found to be a smooth function of temperature.
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Salje, E., Kuscholke, B., Wruck, B. et al. Thermodynamics of sodium feldspar II: Experimental results and numerical calculations. Phys Chem Minerals 12, 99–107 (1985). https://doi.org/10.1007/BF01046834
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DOI: https://doi.org/10.1007/BF01046834