caa a22 4500 378927388 CHVBK 20180305123621.0 cr unu---uuuuu 161128e20041101xx s 000 0 eng 10.1524/ract.92.9.527.54995 doi (NATIONALLICENCE)gruyter-10.1524/ract.92.9.527.54995 Thermodynamics and solubility of (UxNp1-x)O2(am) solid solution in the carbonate system [Elektronische Daten] [Dhanpat Rai, Nancy J. Hess, M. Yui, Andrew R. Felmy, D. A. Moore] The formation of a solid solution can significantly affect the solubility of a minor component. The objectives of this study were to determine the nature of U(IV) and Np(IV) solid solutions and their thermodynamic properties. For this purpose, (UxNp1-x)O2(am) precipitates with values of x varying from 0.05 to 0.95 were prepared, characterized, and used to determine their solubility in dilute to concentrated K2CO3 and KHCO3 solutions. The solubility data show that the equilibrium in these systems is reached in < 7days, the solubility-controlling solids are amorphous, and that we were successful in maintaining U and Np in the tetravalent state. A scanning electron microscope equipped with energy dispersive spectrometry and X-ray absorption spectroscopic analyses of the solids indicated the quilibrated co-precipitates to be solid solutions. A close agreement between the thermodynamic predictions, assuming an ideal solid solution, and the experimental solubilities shows that U(IV) and Np(IV) form an ideal solid solution and that non-ideal solid solution behavior for this system can be ruled out. © 2004 Oldenbourg Wissenschaftsverlag GmbH Laboratory techniques, experiments nationallicence Analytical chemistry nationallicence Inorganic chemistry nationallicence Rai Dhanpat aut Hess Nancy J. aut Yui M. aut Felmy Andrew R. aut Moore D. A. aut Radiochimica Acta/International journal for chemical aspects of nuclear science and technology Oldenbourg Wissenschaftsverlag GmbH 92/9-11/2004(2004-11-01), 527-535 0033-8230 92:9-11/2004<527 2004 92 ract https://doi.org/10.1524/ract.92.9.527.54995 text/html Onlinezugriff via DOI 1 research article jats NATIONALLICENCE 856 40 https://doi.org/10.1524/ract.92.9.527.54995 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Rai Dhanpat aut NATIONALLICENCE 700 1- Hess Nancy J. aut NATIONALLICENCE 700 1- Yui M. aut NATIONALLICENCE 700 1- Felmy Andrew R. aut NATIONALLICENCE 700 1- Moore D. A. aut NATIONALLICENCE 773 0- Radiochimica Acta/International journal for chemical aspects of nuclear science and technology Oldenbourg Wissenschaftsverlag GmbH 92/9-11/2004(2004-11-01), 527-535 0033-8230 92:9-11/2004<527 2004 92 ract CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-gruyter