Compound repetition in oxide-oxide interactions: The system Li2O-V2O5
Abstract
Previous work on compound repetition in oxide-oxide interactions has been extended with studies of the system Li2O-V2O5. It has been found that crystallization from the melt occurs metastably in the high vanadium pentoxide portions of the system with the resultant exclusion of a stable phase, 2Na2O·17V2O5, which melts incongruently at 621°. The phase 2Na2O·5V2O5 has been found to melt congruently at 603° in the metastable equilibria and incongruently at 601° in the stable solid-liquid equilibria. A compound having the composition. Na2O·V2O5 melts incongruently at 616°, while another compound having the composition 3Na2O·V2O5 melts congruently at 1152°. This phase exhibits three crystallographic inversions, at 724, 773, and 1152°. The results of the present work are compared with other reported data on the system Li2O-V2O5 and are used as a basis for prediction of compound repetition in the system Na2O-V2O5.