The magnesium, manganese and nickel uranyl oxide hydrates have been synthesized by the reaction of the appropriate metal salts with schoepite at elevated temperature. After separation from the reaction mixture, the chemical composition of the different compounds was determined, and the chemical formulae were calculated based on different structural hypotheses. X-Ray powder diffraction data were obtained from each of the three species. After indexing and unit-cell parameter determination, the most plausible space groups were proposed, and compared with the known space groups of existing uranyl oxide hydrates.

Thermal analysis was performed to determine the character and the number of water molecules in the structures. The solubility and solubility products were determined, and the influence of the different uranyl species was evaluated. Finally, to examine the presence of a charged double layer, the zeta potential was determined.