Tysonite type Gd1−yCayF3−y solid solution: hydrothermal synthesis and luminescence properties

Abstract

The monodisperse submicroplates of Gd_1−yCa_yF_3−y solid solution were successfully synthesized by a simple and facile hydrothermal method for the first time. The structure of the as-synthesized Gd_1−yCa_yF_3−y was determined to be tysonite-type instead of the usual fluorite-type via a Rietveld refinement method with GSAS. Detailed contrast experiments revealed that the addition amounts of ethylene glycol, calcium chloride, and sodium fluoroborate played critical roles in the formation of the Gd_1−yCa_yF_3−y solid solution. Desirable multicolor outputs were successfully realized by doping activator ions (Eu³⁺, Tb³⁺, and Dy³⁺) in the Gd_1−yCa_yF_3−y crystals where the Gd³⁺ ions served as an energy intermediate. Furthermore, the energy transfer from the Gd³⁺ to Eu³⁺ ions in the obtained Gd_1−yCa_yF_3−y solid solution was more efficient than that in the orthorhombic GdF₃.