Solid state interaction studies on binary nitrate mixtures of uranyl nitrate hexahydrate and lanthanum nitrate hexahydrate at elevated temperatures

Abstract Interaction behavior of uranyl nitrate hexahydrate (UNH) and lanthanum nitrate hexahydrate (LaNH) have been investigated on the mixtures in different molar ratios of the two precursors and monitoring the reactions at elevated temperatures with thermoanalytical and X-ray diffraction measurement techniques. During the decomposition of equimolar mixture of LaNH and UNH, formation of lanthanum uranate (U 0.5 La 0.5 )O 2 , was seen by the temperature of 500 °C along with lanthanum oxide (La 2 O 3 ) and uranium trioxide (UO 3 ). By the temperature of 700 °C, the formation of uranium sesquioxide (U 3 O 8 ) was observed along with (U 0.5 La 0.5 )O 2 as end products in uranium rich mixtures. Lanthanum rich compositions decomposed by the temperature of 700 °C to give (U 0.5 La 0.5 )O 2 and La 2 O 3 as end products.