Effect of Eu3+ concentration on photoluminescence and thermoluminescence behavior of YBO3:Eu3+ phosphor

Monodispersed yttrium aluminum garnet (YAG) powders have been synthesized via homogeneous precipitation method from the mixed solutions of yttrium nitrate, aluminum nitrate, and ammonium aluminum sulfate using urea as the precipitant. The molar ratio of aluminum nitrate to ammonium aluminum sulfate has a significant effect on morphology and particle size of the precursor powders. It was found that spherical precursor particles can be obtained when the ratio is 1:1. During the homogeneous precipitation process, aluminum ions precipitate first and form monodispered spherical powders, and then yttrium ions precipitate onto the surface of the existing spheres. Monodispersed spherical YAG particles with 500 nm in diameter were obtained by calcining the precursor powder at 1100°C for 5 h. The so-prepared monodispersed spherical Nd:YAG powders have good sinterability, and can be sintered into transparent ceramics by vacuum sintering at 1650°C for 3.5 h.

Synthesis of Monodispersed Spherical Yttrium Aluminum Garnet (YAG) Powders by a Homogeneous Precipitation Method

Auto-ignition based synthesis of Y2O3 for photo- and thermo-luminescent applications

The present paper reports the synthesis, photoluminescence (PL), and thermoluminescence (TL) studies of Eu3+-doped yttrium oxide (Y2O3) phosphor using inorganic materials like Y2O3, flux calcium fluoride, and europium oxide. The sample was prepared by the modified solid state reaction method, which is the most suitable for large-scale production. The prepared phosphor sample was characterized using powder X-ray diffraction, field emission gun scanning electron microscopy, high resolution transmission electron microscopy, Fourier transform infrared spectroscopy , PL, TL, and Commission Internationale de I’Eclairage techniques. The PL emission was observed in the range 417–632 nm ranges all visible regions for the Y2O3 phosphor doped with Eu3+. Excitation spectrum found at 254 nm. Sharp intense peaks found around 467, 534, 594, 612, and 632 nm with high intensity. From the XRD data, using the Scherer’s formula, the calculated average crystallite size of Eu3+-doped Y2O3 phosphor is around 45 nm. TL study was carried out for the phosphor with UV irradiation. The present phosphor can act as single host for white light emission in display devices.

Effect of europium concentration on photoluminescence and thermoluminescence behavior of Y2O3:Eu3+ phosphor

Sesquioxide ceramics (Y2O3, Lu2O3 and Sc2O3) along with their solid solutions show great potential as hosts for solid-state laser gain materials due to their great suitability for various rare-earth ions, comparably physical properties to single crystals and far lower preparation temperature than the melting point (above 2400 °C). In this work, the development of the fabrication of rare-earth ions doped-sesquioxide ceramics like synthesis of raw nano-powders and ceramic sintering is reviewed, which demonstrates that the ceramics fabricated by vacuum sintering plus hot isostatic pressing technology from well-dispersive nano-powders possess high transparency with uniform microstructures. And the stable synthesis of powders, optical quality and large-scale preparation of ceramics need further investigation. Meanwhile, the progress on laser performance of the corresponding transparent ceramics is also summarized, which reveals that rare-earth active ions doped sesquioxide ceramics have great potential in efficient high power and ultrashort pulse laser applications during 1∼3 μm.

Research progress and prospects of rare-earth doped sesquioxide laser ceramics

Ammonium sulfate has been widely used as a control agent in the preparation of yttrium-aluminium-garnet (YAG) transparent ceramics, however, research of its application in the preparation in transparent ceramic yttria has not been intensively studied. Neodymium–doped yttria (Nd:Y2O3) nanopowders with controlled morphology and size were synthesized via a urea precipitation method using ammonium sulfate as the additive. The effect of ammonium sulfate was intensively studied throughout the preparation process. Morphology of precursors was found to be evidently affected by the [(NH4)2SO4]/[Nd:Y2O3] ratio (measured by weight). Uniform spheres of Nd:Y2O3 precursor were obtained without the addition of ammonium sulfate. With increasing amounts of ammonium sulfate added, the scale of the Nd:Y2O3 precursors diminished which results in the aggregation of the Nd:Y2O3 precursor. Aggregates of coral like particles after precipitation and uniform well dispersed particles after calcinations were obtained as the dosage of ammonium sulfate reached 20 wt%. It was considered to be the optimum state for the preparation of highly sinterable Nd:Y2O3 nanopowders. Ammonium sulfate was proved to be a regulator that could mediate the nucleation and growth of the precursor as well as its decomposition behaviour. Results of this paper can contribute to the controllable synthesis of transparent ceramic yttria.

Ammonium sulfate regulation of morphology of Nd:Y2O3 precursor via urea precipitation method and its effect on the sintering properties of Nd:Y2O3 nanopowders

Yuanyuan Zhang

Papers

Ammonium sulfate regulation of morphology of Nd:Y2O3 precursor via urea precipitation method and its effect on the sintering properties of Nd:Y2O3 nanopowders