Abstract: It is the first report of using the hydrothermal method to synthesize powder crystal CaWO₄ phosphors whose structure is a kind of tetragonal structure with lattice parameters a=0.5248 nm, c=1.1355 nm. The phosphors have excitation spectra peak at λ_ex=233 nm, and emission spectra peak at λ_em=426 nm. Under 254 nm excitation, the phosphors were measured by FMS-1 chromatic detector, and its chromatic coordinates are x=0.1725, y=0.1424 respectively. The particle size distribution was measured by JWY laser particle size analyzer and its medium diameter is 3.90 μm, D₇₅ / D₂₅=3.93/2.27=1.73, its volume specific surface area is S_V=24368 cm^-1 .

Key words: Hydrothermal synthesis, Calcium tungstate, Phosphor