That the equilibrium state of impurityhyphen;free polycrystalline ice contains water has been expressed in terms of freehyphen;energy changes, and further developed to show that liquid in cavities formed at grain junctions in a microcrystalline solid containing no impurities affects its electrical properties and increases its heat capacity. General formulas for the volume of a liquid contained in the pockets formed at fourhyphen;grain junctions and veins formed at threehyphen;grain junctions in equilibrium in an impurityhyphen;free polycrystalline mass are given. The variation of the volume fraction of intergranular water in impurityhyphen;free ice and the icersquo;s total free energy have been calculated for different grain sizes and temperatures. Calculations also confirm that intergranular water or premelting contributes significantly to the pure icersquo;s heat capacity.
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