Coprecipitation of Ti, Zr and Hf as homologues of Rf with lanthanum fluoride from hydrofluoric acid solutions

The longer half-lives of radionuclides of transactinides 104267Rf and 105268Db discovered in the An+48Ca reactions expand the application of radiochemical techniques for their chemical characterization and to elucidate the influence of relativistic effects on the chemical properties within a group in the periodic table. Here we report the coprecipitation behavior of Ti, Zr and Hf as lighter homologues of Rf with lanthanum fluoride. The kinetics of coprecipitation and distribution of group 4 elements between the liquid and solid phase, both preformed and formed during the distribution process, was studied as a function of concentration of the micro- and macrocomponent, foreign multivalent ions, HF, pH in solution. The solid phase of prepared samples was characterized by electron microscopy (SEM and TEM). The results show that the coprecipitation mechanism of Zr and Hf with LaF3 is different from Ti and Th and can be assigned to heterovalent isomorphism. A possibility of using coprecipitation with lanthanum fluoride for investigation of the behavior of Rf in HF solutions was demonstrated