Mutual separation characteristics for binary mixed oxides Ho2O3–Ln2O3 (Ln = Sc, Y, La, Nd, Sm) using stepwise chlorination-chemical vapor transport reaction mediated by vapor complexes KLnCl4

Mutual separation characteristics for binary oxide mixtures Ho2O3–Sc2O3, Ho2O3–Y2O3, Ho2O3–La2O3, Ho2O3–Nd2O3 and Ho2O3–Sm2O3 using a stepwise chlorination-chemical vapor transport (SC-CVT) reaction mediated by vapor complexes KLnCl4 have been investigated. The total transported yields of the chlorides produced from the oxide mixtures was in the order of <F>HoCl3>ScCl3</F>, <F>HoCl3>YCl3</F>, <F>LaCl3>HoCl3</F>, <F>HoCl3>NdCl3</F> and <F>HoCl3>SmCl3</F>, the main deposition temperature of the chlorides is in the increasing order of <F>ScCl3<HoCl3<YCl3<SmCl3<NdCl3<LaCl3</F>, and the largest separation factors 19.0 for Sc:Ho, 15.3 for Ho:Y, 125.0 for Ho:La, 10.6 for Ho:Nd and 13.6 for Ho:Sm in the lower temperature region, while 1480.0 for Ho:Sc, only 2.1 for Y:Ho, 50.0 for La:Ho, 15.2 for Nd:Ho and 9.0 for Sm:Ho in the higher temperature region were observed, respectively. The results were discussed on the difference of ionic radius of Sc, Y and La on the one side and 4f lanthanides elements of Ho, Nd and Sm on the other hand, and verified that the ionic radius is one of the decisive factors only for lanthanide elements, not for Sc and Y. Furthermore, the SC-CVT characteristics mediated by vapor complexes KLnCl4 of binary oxides Ho2O3–Ln2O3 were studied compared with that of Y2O3–Ln2O3 mediated by KLnCl4 or LnAlnCl3n+3 for the ionic radius of Ho3+ and Y3+ are very near. [Copyright &y& Elsevier]