Phase equilibria in the Li2MoO4-Tl2MoO4-Pr2(MoO4)3 system

The character of phase equilibria in the subsolidus region of the Li2MoO4-Tl2MoO4-Pr-2(MoO4)(3) ternary salt system was established using the method of "crossing joins." The existence of the LiTlPr2(MoO4)(4) ternary molybdate in the LiPr(MoO4)(2)-TlPr(MoO4)(2) pseudobinary join was confirmed. No other intermediate phases were found. It was demonstrated that the LiPr(MoO4)(2)-TlPr(MoO4)(2) join becomes a eutectic one at T > 640 degrees C (the temperature at which solid LiTlPr2(MoO4)(4) decomposes to the corresponding double molybdates). The eutectic temperature is 840 degrees C. Because the character of phase equilibria in the Li(2)MoO(4)Ln(2)(MoO4)(3) and Tl2MoO4-Ln(2)(MoO4)(3) systems does not vary significantly in the Ce-Eu series, it was suggested that other Li2MoO4-Tl2MoO4-Ln(2)(MoO4)(3) ternary systems in which LiTlLn(2)(MoO4)(4) compounds are formed would be characterized by similar subsolidus diagrams.