Synthesis, Luminescence and Optical Properties of a CaMoO₄ Nano-Powder Prepared by Using the Precipitation Method

Nano powders of CaMoO₄ were synthesized by using the precipitation method, and the obtained powders were dried inside a vacuum oven at 120 °C. The phases of powders were analyzed by using X-ray diffraction (XRD), which revealed that CaMoO₄ was free from any extra phases. The surface morphologies of the powders were studied by using transmission electron microscopy (TEM), and the average particle sizes were quite small, being in the range of 7 nm. The optical properties were characterized by using ultraviolet-visible (UV-vis) absorption spectroscopy and the optical energy band gap was found to be 5.51 eV. The fluorescence decay time and the luminescence spectrum of the sample were measured under the excitation by Laser (266 nm), X-ray and proton sources. The obtained results were compared with the CaMoO₄ bulk crystal and sintered powder obtained from the solid state reaction.