Structural model for nitrogen incorporation in phosphate glasses

Abstract

In this paper a model is presented for predicting the structural changes that occur in a metaphosphate glass during nitriding in anhydrous ammonia. Predicted values for the nitrogen content, the mole fraction of phosphate groups, the bridging to nonbridging oxygen ratio, and the ratio of the structural types for nitrogen are compared to the values obtained in earlier experimental work. A plausible correlation is found between the values predicted from this structural model and those observed experimentally. In addition, a maximum nitrogen content (N/P = 0.9) is predicted and the lower nitrogen content normally observed is explained.