Solid-state synthesis, characterization and luminescent properties of Eu3+-doped gadolinium tungstate and molybdate phosphors: Gd(2−x)MO6:Eux3+ (M=W, Mo)

Red phosphors gadolinium tungstate and molybdate with the formula Gd(2−x)MO6:Eux3+ (M=Mo, W) were successfully synthesized by the solid-state reaction at 900 and 1300 °C for 4 h, respectively. The products were characterized by an X-ray powder diffractometer (XRD), TG–DSC, FT-IR, PL, UV–vis and SEM. Room-temperature photoluminescence indicated that the as-prepared Gd(2−x)MO6:Eux3+ (M=Mo, W) had a strong red emission, which is due to the characteristic transitions of Eu3+ (5D0→7FJ, J=0, 1, 2, 3, 4) for these phosphors. Meanwhile, the 5D0→7F2 is in the dominant position. The emission quantum efficiency of Eu3+ in the Gd(2−x)MO6:Eux3+ (M=Mo, W) system has been investigated. The XRD results indicate that both Gd2WO6 and Gd2MoO6 belong to the monoclinic system with space group C2/c [A. Bril, G. Blasse, J. Chem. Phys. 45 (1966) 2350–2356] and I2/a [A. Bril, G. Blasse, J. Chem. Phys. 45 (1966) 2350–2356], respectively. SEM images indicate that the shape of Gd1.96WO6:Eu0.043+ is aggregated small particles with a mean diameter of about 300 nm, and the shape of Gd1.96MoO6:Eu0.043+ is block-like structures.