关键词: 水解氧化, 荧光粉, Y₂O₃

Abstract:

A novel and convenient hydrolysis and oxidation method is used in preparing Y₂O₃ powders. In this work, yttrium carbide was obtained from yttrium and the graphite by melting in a vacuum melting furnace. Y₂O₃ powders were prepared with a hydrolysis and oxidation method. The composition, crystal structure, photoluminescence properties, morphology and microstructure of Y₂O₃ powders were investigated with X-ray diffration(XRD), etc. The following results had been obtained. The triturated alloys sized about 1 mm were introduced into deionized water with 1∶20 mass ratios and PEG-400 and deionized
water with 8∶100 volume ratio under agitation for 24 h at 25°C. After filtering, washing and deionized water drying in a cabinet at 80 °C, and 400~1 000°C heat treatment, Y₂O₃ powders were obtained. Crystallization peaks appeared around 400°C. These XRD data were entirely consistent with the PDF card No. 65-3178, showing that the samples were cubic Y₂O₃. When the annealing temperature was raised to 800°C, the sample exhibited fluorescence. The obtained powders showed good bluish-white PL emissions, ranging from 430 to 600 nm, with peaks at 468 and 578 nm, under xenon light excitation. The luminescent mechanism was ascribed to the breakage of C—OY and COOY structures, giving rise to photoluminescence through a strong electron-photon coupling.

Key words: hydrolysis and oxidation, phosphor, Y₂O₃