The Reaction of GaP(s) with H[sub 2]O(g) and the Range of Stability of GaP(s) under Pressures of Ga[sub 2]O and P2

The reaction of with wet hydrogen has been studied by a vapor transport method. Experimental equilibrium constants in the temperature range of 800°–1100°C have been found to be in satisfactory agreement with the equilibrium constants calculated from the free energies of formation of the reacting components, , , and . A heat of formation of at 298°K of −42.75 kcal/mole has been obtained from the Knudsen cell measurements of Johnston. A value of for of 14.4 cal/deg mole has also been obtained. The range of pressures of and P 2 over which is stable is described. Formation of both and is considered. Variation in the solubility of oxygen in as a function of the pressures of and P 2 is discussed.