摘要
研究了H3BO3在碱土铝酸盐长余辉发光材料中的作用 ,发现H3BO3不但影响固相反应速度 ,还对粉体晶相组成、粒径以及长余辉发光性能产生很大的影响。TG DTA ,XRD和SEM分析表明 ,H3BO3参与了固相反应 ,降低了成核温度与界面反应能垒 ,使晶粒生长反应速度加快 ,粉体粒径增大。激发与发射光谱、发射峰强度衰减以及热释光谱分析表明 ,H3BO3的掺入使发光中心离子浓度增加、陷阱深度和密度加大 ,从而使发光亮度增加 ,余辉寿命延长。
It is well known that H_3BO_3 is used as a flux which can decrease the temperature of solid state reaction in SrAl_2O_4∶Eu, Dy phosphor. But much recent researches showed that H_3BO_3 addition in SrAl_2O_4∶Eu, Dy phosphor not only works as a flux, but also plays an important role in phase stability and long phosphorescence of SrAl_2O_4∶Eu, Dy. In this paper the effects of H_3BO_3 addition in SrAl_2O_4∶Eu, Dy is studied and the mechanism is investigated. The results show that H_3BO_3 not only quickens solid state reaction but also affect crystal composition, grain size and long phosphorescence of SrAl_2O_4∶Eu, Dy. Results of TG-DTA, XRD and SEM indicate that H_3BO_3 takes part in the solid state reaction and the B^(3+) from H_3BO_3 occupy the sites of Al^(3+) in crystal lattice. Owing to better reactivity of B_2O_3 decomposed from H_3BO_3, crystal seeds are formed at lower temperature and thus interface reactions also begin at lower temperature. This makes the crystal grow more quickly and result in bigger grain size. From photoluminescence and afterglow decay properties of samples, it can be found that doping B^(3+) in SrAl_2O_4∶Eu, Dy can improve powders′ luminance and prolong afterglow life. In order to investigate whether trap depth and density are changed after doping B^(3+), thermally stimulated luminescence was measured and the results show that trap density is increased and trap depth is deepened with the use of H_3BO_3, and the more amount of doped B^(3+) is, the bigger trap density and deeper trap depth are.
出处
《中国稀土学报》
CAS
CSCD
北大核心
2004年第3期312-317,共6页
Journal of the Chinese Society of Rare Earths
基金
湖南省自然科学基金项目 ( 0 2JJY3 0 44 )
关键词
无机化学
硼酸
铝酸盐
长余辉
稀土离子
inorganic chemistry
boric acid
aluminate
afterglow
rare earth ion
