Metal carboxylate precursors for ceramic materials and waste forms for radionuclides

Novel metal carboxylate precursors for ceramic materials have been developed which provide extremely low deposition temperatures and/or precise control of metal stoichiometry.;Low temperature metal oxide precursors based on metal complexes of ;Precise stoichiometry precursors for ferrite and perovskite materials have been designed, which fix the metal to metal ratios by crystallization processes. High purity mixed metal oxalates of the type MTiO(Ox)2 ;Precise stoichiometry mixed ferrite precursors have been prepared in a similar procedure, in which the readily available starting material NaFeEDTA has been ion exchanged to the corresponding proteo-derivative and subsequently reacted with water soluble salts of divalent metals such as Ni, Mg, Co and Cu. This procedure yields the mixed metal ferrite precursors as crystalline compounds in excellent purity without any sodium contamination.;The MOD approach has also been utilized for encapsulation of radionuclides into Synroc mineral phases. Three different MOD procedures have been designed which use different carboxylate ligands and encapsulation procedures. The first two approaches utilize NaPAO/disodium fumarate and sodium polyacrylate to precipitate the radionuclides and the Synroc forming elements from aqueous solution. Firing of this precipitate to ceramics results in the encapsulation of all but the alkali metal radionuclides into Synroc mineral phases. The third procedure involves conversion of the nitrate salts (in which form the radionuclides in radwaste are usually present) to acetates by reduction of the nitrate ions with excess acetaldehyde in acetic acid. Removal of the acetic acid solvent furnishes an amorphous acetate precursor, the pyrolysis of which at 800...