Synthesis and Characterization of a CsBaGd(MoO 4 ) 3 :Er 3+ /Yb 3+ Phosphor with a Scheelite-Like Structure

— We have investigated phase relations along a number of joins in the subsolidus region of the Cs 2 MoO 4 –BaMoO 4 –Gd 2 (MoO 4 ) 3 system using X-ray diffraction and differential thermal analysis and constructed its phase compatibility diagram. A ternary molybdate with the composition CsBaGd(MoO 4 ) 3 and a monoclinic scheelite-like structure (sp. gr. P 2 1 / n ) has been synthesized. Codoping CsBaGd(MoO 4 ) 3 with Er 3+ /Yb 3+ ions, we have obtained an upconversion phosphor exhibiting anti-Stokes luminescence in the range 400–700 nm under IR excitation (λ ex = 977 nm). The synthesized phosphor has been characterized by X-ray diffraction, differential thermal analysis, and vibrational spectroscopy, and its luminescence spectrum has been measured.