Synthesis, structural and optical characterization of Eu:KYb(WO4)2 nanocrystals: A promising red phosphor

The modified Pechini method was used to synthesize europium-doped potassium ytterbium tungstate, 50 at.% Eu in KYb(WO4)2, nanocrystals. This method is based on polyesterification between ethylenediaminetetraacetic acid and ethylene glycol, which produces the material at low temperature (1073 K). The structural characterization study was carried out by X-ray powder diffraction analysis and showed that the nanocrystals crystallized in a monoclinic system with the space group C2/c and unit cell parameters a = 10.667(2) Å; b = 10.437(2) Å; c = 7.585(1) Å; β = 130.866(8)°, Z = 4. The mean and the particle size dispersion were studied by the Scherrer’s equation and electron microscopy. Optical absorption and emission were performed in order to obtain a detailed spectroscopic study of trivalent europium in the monoclinic double tungstate nanocrystals.