Production of nanocrystalline Y2O3:Eu powder by microwave plasma-torch and its characterization

Y2O3:Eu red-emitting nanophosphors were synthesized directly by dissolving Y2O3 and Eu2O3 in HNO3 and by using an atmospheric microwave-plasma torch for a direct continuous preparation and for mass production of Y2O3:Eu powders. Atmospheric microwave plasmas produce a high-temperature plasma flame due to ohmic heating by high frequency electric fields, revealing a maximum central temperature of 6500 ± 350 K. Therefore, the synthesized Y2O3:Eu nanophosphors from instantaneous evaporation of dissolved Y2O3 and Eu2O3 in HNO3 have favorable characteristics such as regular size and cubic equilibrium structure. The nanophosphors were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), and photoluminescence (PL).