Trends in rare earth thiophosphate syntheses: Rb3Ln(PS4)2 (Ln = La, Ce, Pr), Rb3−xNaxLn(PS4)2 (Ln = Ce, Pr; x = 0.50, 0.55), and RbEuPS4 obtained by molten flux crystal growth†
Abstract
Single crystals of new rubidium rare earth thiophosphates with the formulas Rb3Ln(PS4)2 (Ln = La, Ce, Pr), Rb3−xNaxLn(PS4)2 (Ln = Ce, Pr; x = 0.50, 0.55), and RbEuPS4 were crystallized out of a molten RbCl flux. The compounds Rb3Ln(PS4)2 (Ln = La, Ce, Pr) and Rb3−xNaxLn(PS4)2 (Ln = Ce, Pr; x = 0.50, 0.55) both crystallize in the monoclinic crystal system adopting the space groups P21 and P21/c, respectively, while RbEuPS4 crystallizes in the orthorhombic crystal system adopting the space group Pnma. A survey of all known rubidium rare earth thiophosphates grown using an alkali halide flux revealed trends suggesting that the Rb3Ln(PS4)2 and Rb3−xNaxLn(PS4)2 families of compounds can be actively targeted over a wide range of temperatures by employing RbCl as at least a component of the flux. Fluorescence measurements were performed on all compounds obtained, revealing resolved f–f transitions in Rb3Pr(PS4)2 and Rb2.45(2)Na0.55(2)Pr(PS4)2 and only single broad emission peaks for Rb3Ce(PS4)2 and Rb2.50(6)Na0.50(6)Ce(PS4)2, behavior characteristic for cerium(III) compounds.
- This article is part of the themed collections: Crystal Growth and Editor’s Collection: Rare Earth Materials