Thermodynamic study on elimination of platinum inclusions in phosphate laser glasses for inertial confinement fusion applications

A new method to calculate the formation enthalpies and free energies of compounds based on standard electromotive force of cation, φ0, and free energies of formation, G 298 0 , or formation enthalpies, H 298 0 , of chloride was proposed. A linear relationship between φ0 and G 298 0 , φ0 and H 298 0 , and G 298 0 , and H 298 0 was found respectively. The parameters used for thermodynamic calculation were calculated. The calculated values of the formation enthalpies and the free energies of formation of platinum compounds, such as Pt3,(PO4 21, and Pt(PO3)2, were given for the first time. The mechanism of eliminating platinum inclusions in phosphate laser glass by POCl3, gas bubbling was interpreted from thermodynamic aspect.