Search

Abstract: The BaMgAl10O17:Eu2+ (BAM) as an efficient blue-emission phosphor has been used in tricolor fluorescent lamps (FLs) and plasma display panels (PDPs) because it has a deep blue color and a short decay time, but in the process of FL manufacturing, BAM, which spreads on the insides of a glass tub, is heated at 700–750 °C in air. The PDP manufacturing process also heats phosphor at 500–600 °C to make phosphor layers. These heat-treatments result in the luminance decrease. In this work, the BAM phosphors are covered with uniform and continuous MgO coatings via a precipitation route, which is expected to inhibit their surface oxidation. The results indicated that thermal stability was largely improved. [Copyright &y& Elsevier]

Abstract: The composite of hollow glass microspheres coated by SnO2 nanoparticles has been successfully fabricated via sol-gel method. The phase structures, morphologies, particle size, shell thickness, chemical compositions of the composite have been characterized by XRD, FESEM, and EDX. The results show that SnO2 coating on hollow glass microspheres can be achieved, and the coating layers are constituted by SnO2 nanoparticles of mean size ca. 15 nm. The SnO2 coating layers grow thicker with the increased concentration of SnCl4. The effects of parameters (reaction temperature, concentration of NaOH and SnCl4, and time) were investigated to yield SnO2 coating on hollow glass microspheres, and the UV–vis absorption spectra of the composites were studied. [Copyright &y& Elsevier]

Abstract: Magnetic nanoparticles of cobalt ferrite have been synthesized at different temperatures without any subsequent heat treatment. The particle size, crystal structure and magnetic properties of as-synthesized particles were investigated by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, Raman spectroscopy and vibrating sample magnetometer. The nanoparticles are of cubic spinel structure and equiaxial shape. The average size of nanoparticles increases with the increase of reaction temperature. Magnetic properties of nanoparticles show strong dependence on the particle size. A maximum coercivity of 3267 Oe and a maximum remanence ratio of 0.58 are obtained from the sample synthesized at 80 °C. [Copyright &y& Elsevier]