Uranates(VI) and tungstates(VI) within the system Li 2OUO 3WO 3

Abstract

The system Li 2OUO 3WO 3, which was investigated between 300 and 1600°C at 1 atm O 2, contains the compounds Li 6WO 6Li 6UO 6, Li 4WO 5Li 4UO 5, Li 2WO 4Li 2UO 4, Li 2W 2O 7, Li 2W 4O 13, LiU 0.83O 3, Li 2U 3O 10, Li 2U 6O 19, UWO 6 and UW 3O 12. Lithium uranates(VI) and -tungstates(VI) with high Li 2O-content show an octahedral coordination of uranium and tungsten in closely related crystal structures and can form some solid solutions. At low Li 2O-content uranium forms strong uranyl bonds whereas tungsten prefers tetrahedral coordination with very little solid solution of uranium.