Phase equilibria in the La2O3-Nb2O5-Nb system and thermal stability of compounds with low degree of niobium oxidation.
The phase equilibria in the ternary system La2O3-Nb2O5-Nb have been studied at subsolidus temperatures in vacuum (6.65 × 10−3 Pa), and the temperature stability limits of LaNb7O12 have been determined in vacuum and during heating in air.