稀土长余辉发光材料的研究现状和发展趋势

回顾了不同稀土长余辉发光材料的研究进展;讨论了稀土长余辉发光材料的发光机理;对稀土长余辉发光材料存在的问题和进一步的发展进行了探讨。     

稀土长余辉发光材料的研究进展

长余辉发光材料是属于光致发光材料的一种,是指经日光和长波紫外线等光源的短时间照射,关闭光源后,仍能在很长一段时间内持续发光的材料。由于稀土长余辉发光材料的储光-发光的特性,它们可作为发光涂料、发光薄膜、发光油墨、发光纤维、发光纸等,在建筑装潢、军事设施、交通运输、消防应急等领域得到了广泛应用。     

稀土长余辉发光材料

20世纪90年代以来，为了发展更优良的长余辉发光材料，人们尝试使用稀土，成功开发了二价铕和其他稀土离子掺杂的绿色、蓝绿色及蓝色长余辉发光材料。目前商用的蓝色长余辉发光材料是铕、     

氨基硅烷偶联剂表面修饰稀土长余辉发光颜料的研究

用两种氨基硅烷偶联剂对铝酸盐长余辉发光材料SrMgAl4 O8:Eu2+,Dy3+进行了表面修饰改性.通过水解pH值、电导率、ATR-FTIR、接触角及SEM表征了改性前后样品的变化.结果表明:YDH-550改性效果较好;样品余辉衰减曲线表明,表面改性对其发光性能影响不大.     

稀土离子掺杂对长余辉发光玻璃发光性能的影响

选择制备了系列Eu^2＋，Dy^3＋共掺杂的硼铝酸锶长余辉发光玻璃。利用发光光谱、余辉衰减曲线、热释光谱系统研究了稀土离子掺杂对长余辉玻璃发光性能的影响。研究结果表明，不同掺量组合的Eu^2＋及Dy^3＋对长余辉玻璃发光性能有不同影响，在Eu^2＋及Dy^3＋掺量比为l：l（摩尔比）的情形下，随Eu^2＋离子掺量的增多，发光性能下降；在Eu^2＋及Dy^3＋掺量比为1：2的情形下，随Eu^2＋离子掺量的增多，发光性能增强。在此实验基础上，围绕缺陷形态及其与稀土离子间的能量传递，提出了可能的长余辉机制。     

稀土长余辉发光材料在消防标志中的应用进展

从蓄光型光致发光型标志牌的特点、组成、制作方法、目前的应用状况等角度综述了稀土长余辉发光材料在消防标志中的应用进展,分析了该领域目前发展的不足之处,为该领域今后工作的发展重点提出了建议.     

铝硅酸盐掺杂稀土蓝色长余辉发光材料的研究

研究了掺Si的Sr4Al14O25:Eu,Dy体系晶体结构,光谱特性以及热释发光曲线.结果表明,Sr3.92Al13.95Si0.05O25∶Eu0.042+,Dy0.043+能级陷阱为-0.667eV,掺硅后有利于提高该长余辉材料的初始发光亮度.其次,通过调整Eu2+浓度,实现荧光粉的y色坐标从0.211到0.295变化可调.     

聚焦稀土发光材料着力稀土研发及应用

四川省新力集团公司是以稀土发光材料为产品的集生产、研发与应用为一体的高新技术企业。目前，我公司的主要产品是稀土长余辉蓄光发光粉及相关的下游产品，诸如长余辉标志、标牌及导向标识等，主要应用在交通、消防及地名标识等方面。     

稀土掺杂Sr2MgSi2O7长余辉发光材料的研究进展

硅酸镁锶(Sr2MgSi2O7)作为目前常用的一种长余辉发光材料基质,性能稳定,耐酸碱性能良好。本文介绍了长余辉发光材料的发光原理,综述了近年来Sr2MgSi2O7长余辉发光材料的主要制备方法以及稀土掺杂Sr2MgSi2O7材料的研究进展,并对该材料的发展做出了展望。制备Sr2MgSi2O7长余辉发光材料的方法主要包括高温固相法,溶胶-凝胶法,化学沉淀法和燃烧合成法,其中最常用的为高温固相法。通过掺杂稀土离子可以形成具有不同发光特性的长余辉发光材料。稀土掺杂Sr2MgSi2O7材料作为一种储能、节能的长余辉发光材料,展现出了广阔的发展和应用前景。     

燃烧法合成新型蓝色硅酸盐长余辉材料及其发光性能的研究

采用燃烧法快速合成了Sr2MgSi2O7：Eu^2 ，Dy^3 新型蓝色长余辉材料，用x射线粉末衍射表征材料的相组成和晶体结构，用激发和发光光谱、余辉亮度对材料的发光性质进行表征并对该体系发光机制进行了讨论。结果表明，燃烧法和高温固相法合成的这种长余辉材料具有相同组成和结构，燃烧法可以快速制备出细粉体。合成材料的激发带峰值位于356nm，发射光谱峰值在475nm，是典型的Eu^2 的4f-5d跃迁所产生，余辉时间5h以上。     

Long afterglow yellow luminescence from Pr3+ doped SrSc2O4

A yellow emitting long afterglow luminescence material SrSc₂O₄:Pr³⁺ was successfully prepared by solid state reaction method. SrSc₂O₄:Pr³⁺ phosphor shows a long afterglow luminescence peak at about 495, 545, 621, 630 and 657 nm, respectively, corresponding to the f–f transitions of Pr³⁺. The afterglow chromaticity coordinates of SrSc₂O₄:1 at%Pr³⁺ were calculated to be (0.35, 0.41), indicating that the afterglow emission is close to the light of yellow region. And, the afterglow luminescence of the optimal sample doped by 1 at%Pr³⁺ can persist for over 3 h. The thermoluminescence results suggest that there are three types of traps with depth of 0.61, 0.69 and 0.78 eV exiting for all the samples, which are produced by the addition of Pr³⁺ ions. The trap density of SrSc₂O₄:1 at%Pr³⁺ is the maximum when the incorporation of Pr³⁺ ions reaches 1 at%, which thus results in the longest afterglow luminescence. All the results indicate that SrSc₂O₄:Pr³⁺ can be a potential candidate of novel long afterglow phosphors.     

蓝色长余辉发光材料CaAl2O4∶Eu2+, Dy3+的制备

用溶胶—凝胶法(Sol—gel)制备蓝色长余辉发光材料CaAl2O4∶Eu2+,Dy3+(CED),用差热分析(DTA)、红外光谱分析(IR)、X射线粉晶衍射(XRD)、荧光光度计对合成制备产物进行了系列分析测定,确定了制备的最佳条件,产物的激发波长为328nm,发射波长为440nm。     

SrAl2O4 :Eu2+, Dy3+ Long Afterglow Phosphors Prepared by Chemical Coprecipitation Method

SrAl2 O4: Eu2 , Dy3 long afterglow phosphors were prepared by chemical coprecipitation method. Ammonium carbonate and ammonium hydrogen carbonate were used as the precipitants. The preparation of the SrAl2 O4: Eu2 ,Dy3 precursor was completed at room temperature by controlling the concentration of the metal-salt solution, pH value of the system, etc. The phosphors were prepared by sintering the precursor at 1000 ～ 1200 ℃ in a weak reducing atmosphere for 2 h. The XRD, SEM, excitation spectra, emission spectra and afterglow decay of the samples were tested and the optimal synthesis conditions of the SrAl2O4: Eu2 , Dy3 long afterglow phosphors prepared by precipitation method were determined. The phosphor which had good luminescent properties is prepared and its persistent time can reach more than 1600 min. In the coprecipitation process, a small amount of glucose operates to refe the luminescent powders. The particle size of the phosphor can be less than 1 μm. The sintering temperature of the sample prepared by the coprecipitation method is much lower than that of the one prepared by the high temperature solid state method.Compared with the high temperature solid state method, a clear blue shift occurs in the excitation and emission spectra of the samples.     

Synthesis of Long Afterglow Phosphors MAl2O4:Eu2+, Dy3+(M=Ca, Sr, Ba) by Microemulsion Method and Their Luminescent Properties

Long afterglow phosphors MAl2O4:Eu2 , Dy3 (M=Ca, Sr, Ba) were synthesized by microemulsion method, and their crystal structure and luminescent properties were compared and investigated. XRD patterns of samples indicate that phosphors CaAl2O4:Eu2 , Dy3 and SrAl2O4:Eu2 , Dy3 are with monoclinic crystal structure and phosphor BaAl2O4:Eu2 , Dy3 is with hexagonal crystal structure. The wide range of excitation spectrum of phosphors MAl2O4:Eu2 , Dy3 (M=Ca,Sr,Ba) indicates that the luminescent materials can be excited by light from ultraviolet ray to visible light and the maximum emission wavelength of phosphors MAl2O4:Eu2 , Dy3 (M=Ca, Sr, Ba) is found mainly at λem of 440 nm (M=Ca), 520 nm (M=Sr) and 496 nm (M=Ba) respectively, the corresponding colors of emission light are blue, green and cyna-green respectively. The afterglow decay tendency of phosphors can be summarized as three processes: initial rapid decay, intermediate transitional decay and very long slow decay. Afterglow decay curves coincide with formula I=At-n, and the sequence of afterglow intensity and time is Sr＞Ca＞Ba.     

Application of Rare Earth in Steel in China

Application of rare earth in steels has gone through three stages in China.The investigation of rare earthadding method begun at the late 1970's has solved the technical problems caused by rare earth addition.Controlling sulphide morphology,several rare earth treated steel grades with improved properties have been developedand put into production.Rare earth exerts remarkable effect on the performance of low sulphur steel and on thehydrogen behavior in steel.Rare earth used for surface treatment of iron and steel materials expands rare earthutilization.     

稀土在钢中的应用

本文阐述稀土在钢中的作用机理和加入方法,分析了稀土应用的前景。对钢液进行稀土处理是我国发展钢产业的重要技术手段之一。     

钇的应用与开发前景

本文叙述了稀土元素钇在超导体、结构陶瓷、耐火材料、发光材料、激光材料、高性能合金、高温涂层、致冷技术、航天航空工业、钢铁工业及医学等方面的应用开发情况。