Synthesis and luminescent properties of monodispersed spherical Ce(IV)-Gd(III)-Eu(III) oxides

CECILIA SORBELLO; M. JOBBAGY; B. C. BARJA

Muenster

Conferencia; 1st Rare Earth Elements and Compounds Conference (REEC),; 2012

Introduction: Lanthanides are widely used to develop phosphors with technological applications in the field of light conversion: luminescent lamps, diodes, and optical fibers. A family of ternary compounds with the general formula Ce0.95-xGdxEu0.05O2-, with 0≤ x ≤0.95 was synthesized by the urea method. Spherical and monodispersed luminescent microparticles were obtained. Materials and Methods: Spherical monodispersed hydroxocarbonate precursors were obtained by the homogeneous urea method, reaching after annealing at 1273K the formula Ce0.95-xGdxEu0.05O2- with 0 ≤ x ≤ 0.95. The samples were named CGX, being X the % Gd(III)/[Gd(III)+Ce(IV)]. High resolution scanning electron microscopy (HRSEM) coupled with Energy dispersive X-ray spectroscopy (EDS) was performed. Average particle size = 100 nm. Results and Discussion: The XRD studies indicate that for X > 0.5 only one C-type phase exists. For X < 0.2, a doped CeO2-like phase (cerianite) prevails while, presumably two segregated phases are present for 0.2< X