【作者】 李炳伟；

【导师】 周新木；

【作者基本信息】 南昌大学 ， 无机化学， 2007， 硕士

【摘要】 本文评述了长余辉材料制备、性能和机理的研究现状，针对其存在的主要问题，着重研究了CaTiO3：Pr的长余辉性能。通过固相反应得出了制备CaTiO3：Pr较好的工艺条件，在此基础上分别对基质和激活剂进行了共掺杂并研究了包膜与退火对CaTiO3：Pr发光性能的影响。通过对样品的荧光光谱、XRD、SEM、EDS、热释光谱、紫外可见吸收光谱的研究建立了CaTiO3：Pr的余辉模型，提出了相对发光强度的概念。得出CaTiO3：Pr中主要缺陷为：V″Ca、PrCa、Vo、TiTi4+3+，对长余辉有贡献的是前两种，余辉衰减为三段式衰减。基质掺杂离子原子半径的差异使Pr3+所处晶体场对称性下降是影响其性能的主要因素。等价掺杂时，掺杂离子电负性大有利于样品的余辉性能；Gd3+、Y3+非等价取代Ca2+时样品的余辉性能下降。Eu3+、Sm3+可以向Pr3+传递能量，但在钛酸盐基质中不能被高效的直接激发，亦不能有效的吸收基质晶格的能量，没有从根本上改进样品的长余辉性能。Dy3+在CaTiO3：Pr中可被激发，但不存在向Pr3+能量传递现象。Nd3+、Tb3+、Ho3+、Tm3+在CaTiO3：Pr中不被激发，其掺杂使CaTiO3：Pr发光性能和余辉性能的下降。对样品进行退火和包膜处理可以改善样品的晶体结构，减少氧空穴，增加样品的发光强度和余辉时间。更多还原

【Abstract】 This article discussed the preparation, the performance and the mechanism oflong afterglow material at present, faced the main question in view of it, hasemphatically studied the CaTiO3:Pr long afterglow performance. Good technologicalconditions obtained for preparing the CaTiO3:Pr through the solid phase reaction.Based on the obtained better craft conditions, we reseached the influence of codopentseparately carried on the matrix and the activating agent, and we studied the influenceof annealing and coating film on CaTiO3:Pr.We built the long afterglow model of CaTiO3:Pr by characterization, such asSEM, EDS, PL, TL, as well as luminescence decay. We brought forward the relativeluminous intensity concept and thought that the main defeats include V″Ca、PrCa、Vo、TiTi4+3+ in CaTiO3:Pr, the former two defeats boost the sample’s performance. Thedecay curve showed the process was a three-period process.The difference of atomic radius of doping ion changed the symmetry of crystalfield in which Pr3+ located and is the primary factor affecting CaTiO3:Pr performance.The electric-negativity of doping ions is greatly advantageous to the sample’sperformance when substitution was equal doping in electric-value. The afterglowperformance of samples weaks after Gd3+ or Y3+ substituted Ca2+ respectively. Eu3+,Sm3+ can transfer the energy to the ion Pr3+ but they cannot be directly stimulatedeffectively by UV and not be able to absorp effectively the enery from matrix crystallattice, so they cannot improve the long afterglow, performance. Dy3+ can bestimulated by UV in CaTiO3:Pr, but can not transfer energy to the Pr3+. Nd3+, Tb3+,Ho3+, Tm3+ are not stimulated in CaTiO3:Pr, they cause the CaTiO3:Pr illuminationperformance and the afterglow performance drop.The process of annealing on CaTiO3:Pr can improve the sample’s crystalstructure, reduce the oxygen hole, thereby improve sample’s performance. By coatinga ZrO2 film on the surface of the materials, the results show that surface faults isreduced, the intensity of luminescence spectra become stronger, the TL spectrabecome broader and the peak of it moves to the higher temperature, these mean thecoated sample has better performance than the uncoated.更多还原