红色长余辉发光材料Sr_5Al_2O_7S∶Eu~(2+)的制备及发光性能

以工业铝酸钠溶液制备的氢氧化铝为原料,采用高温固相反应法合成了Sr5Al2O7S∶Eu2+红色长余辉材料。用X射线衍射仪及荧光分光光度计对材料的物相及光谱性能进行了分析,考察稀土掺杂量对样品发光性能的影响。结果表明,在稀土激活剂的掺杂量x(Eu)=6%、硼酸加入量9%、1 200℃烧结8h的条件下合成的样品为Sr5Al2O7S∶Eu2+的纯相,激发光谱位于400～500nm,主发射波长在600nm左右,余辉为桔红色。     

共沉淀法制备长余辉发光材料CaWO4:Eu3+的研究

用共沉淀法制备CaWO4:Eu3 纳米长余辉发光材料.用XRO表征了所得长余辉发光材料的形态和物相组成,用荧光分光光度计测定了长余辉发光材料的发光性能.确定了用共沉淀法制备CaWO4:Eu3 长余辉发光体的最佳条件,其最佳煅烧温度为700℃,煅烧时间为2h.结果表明,共沉淀法制备的CaWO4:Eu3 长余辉发光材料比高温固相法所得材料有更好的长余辉性能.     

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。     

铝酸锶长余辉发光材料包覆无机膜的研究

为提高铝酸锶长余辉发光材料的耐热性,采用表面包覆无机膜的方法;研究工作证明,SEM、EDS、X衍射分析是较好的检查包覆状况的测试方法;采用化学沉积包覆氧化铝膜或二氧化硅膜都可以有效地将发光材料的耐热性提高,其中后者具有包覆工艺简单,成本低的优点,是较好的包覆材料.     

溶胶-凝胶法制备长余辉发光材料SrAl2O4:Eu2+,Dy3+的研究

用溶胶-凝胶法制备长余辉发光材料SrAl2O4∶Eu2+,Dy3+,选用柠檬酸合成前驱体柠檬酸盐,确定最佳烧结温度在1200～1250℃范围,比一般高温固相法制备该产物降低了200℃,其产物的发射光谱出现了明显"蓝移"现象.     

溶胶—凝胶法制备长余辉发光材料SrAl_2O_4∶Eu~(2 ),Dy~(3 )的研究

用溶胶—凝胶法制备长余辉发光材料 Sr Al2 O4 ∶ Eu2 ,Dy3 ,选用柠檬酸合成前驱体柠檬酸盐 ,确定最佳烧结温度在 12 0 0～ 12 5 0℃范围 ,比一般高温固相法制备该产物降低了 2 0 0℃ ,其产物的发射光谱出现了明显“蓝移”现象。     

共沉淀法制备Al/Cr_2O_3复合粒子及其性能研究

采用共沉淀法将Cr2O3复合于片状金属铝粉表面获得了包覆效果好的Al/Cr2O3复合粒子。为了保证复合粒子的红外隐身性能,对前躯体粒子Al/Cr(OH)3进行了TG-DSC测试,确定了对前躯体的热处理温度;同时借助于XRD,SEM测试对制得的Al/Cr2O3粉末的相组成和形貌进行了表征,此外,将Al/Cr2O3粉末制成红外隐身涂层进行红外辐射率性能测试。结果表明,当铝粉含量为50%(质量分数)时制得的Al/Cr2O3复合粒子包覆较为完整,红外辐射率值最低为0.77。Cr2O3对片状Al粉的包覆在降低红外辐射率的同时不仅避免了Al粉的"显形"和氧化,其本身的绿色还可以起到可见光隐身的效果,在林地的迷彩隐身中具有重要的应用价值。     

合成工艺对蓝绿色长余辉荧光粉Sr4Al14O25:Eu,Dy发光性能的影响

采用高温固相反应法合成了蓝绿色长余辉荧光粉Sr4Al14O25:Eu2 ,Dy3 ,考察了合成温度、保温时间、升降温速度及硼酸加入量等对荧光粉余辉性能的影响.研究结果表明,荧光粉在1450℃合成时余辉亮度较高,装料量不同时应选择对应合适的烧结时间.升降温速度实验表明,150℃/h和300℃/h的升温速度明显优于450℃/h的升温速度,600℃/h的降温速度略优于200℃/h、400℃/h的降温速度;H3BO3的掺入能显著提高Sr4Al14O25:Eu2 ,Dy3 的发光性能,但过多的H3BO3也会对产品粉碎时的亮度损耗产生严重影响,最终确定H3BO3的掺量为0.08mol时较为合适.     

SrAl2O4∶Eu2+,Dy3+磷光粉低成本制备工艺及发光性能研究

以工业铝酸钠溶液制备的氢氧化铝为铝基原料,采用高温固相反应法合成了SrAl2O4∶Eu2+,Dy3+磷光粉,考察了稀土掺杂量、烧结温度及硼酸加入量对其发光性能、激发光谱及发射光谱的影响,并通过XRD谱及余辉衰减曲线对最佳工艺条件下制备的样品进行表征。结果表明,当稀土掺杂量x(Eu)=3%、x(Dy)=3%,烧结温度为1 300℃,烧结时间为4h,硼酸加入量w(H3BO3)=9%时,所制备磷光粉样品仍保持SrAl2O4的晶体结构,其发光性能最好,发光强度最大,主激发波长在360nm左右,主发射波长在510nm左右;余辉为黄绿色,衰减时间长。     

制备方法对( Ce0.6Zr0.4O2)0.5(Al2O3)0.5储氧材料性能的影响

分别利用氨水共沉淀法和柠檬酸溶胶-凝胶法制备稀土储氧材料( Ce0.6Zr0.4 O2)0.5(Al2 O3)0.5,并用XRD、BET、H2 - TPR、SEM和EDX等手段研究制备方法对(Ce0.6 Zr0.4 O2 )0.5( Al2O3 )0.5的晶相结构、比表面积、平均孔径、孔容、储氧性能、还原性能、样品各组分含量以及颗粒形貌的影响.结果表明两种方法制备样品均为立方晶相的CeO2 - ZrO2 - Al2 O3固溶体,无Al2O3的晶相.但与氨水共沉淀法比较,柠檬酸溶胶-凝胶法制备样品的比表面积、孔容较大,储氧性、还原性和热稳定性能较高.SEM和EDX测试结果表明,氨水共沉淀法制备样品有明显的聚集现象,而柠檬酸溶胶-凝胶法制备样品的颗粒粒径小,分布均匀,且原子组成更接近理论值.     

Preparation of Incompact Strontium Aluminate Phosphors

The incompact long afterglow pigment SrAl2O4: Eu, Dy was synthesized by ceramics technology.The agglomerated starting raw material had little effect on the synthesis of SrA12O4 matrix through solid-state reaction method,but the shrinkage and densification was retarded greatly by the agglomerated powder by the formation of large and extensive pore network.The sintering mechanism is surface diffusion ( without flux B2O3 ) and grain boundary diffusion (with B2O3 as flux)respectively, and the as-prepared long afterglow pigment glows in the dark for over 4000 min.     

Investigations on Valence-Change Behaviors of Europium Ions in Eu-Doped Aluminate and Silicate Phosphors

Compounds of Sr3Al2O6∶Eu, Sr4Al14O25∶Eu, and BaZnSiO4∶Eu were synthesized by high-temperature solid state reactions. The doping Eu3 ions were partially reduced to Eu2 in Sr4Al14O25∶Eu and BaZnSiO4∶Eu prepared in an oxidizing atmosphere, N2 O2. However, such an abnormal reduction process could not be performed in Sr3Al2O6∶Eu, which was also prepared in an atmosphere of N2 O2. Moreover, even though Sr3Al2O6∶Eu was synthesized in a reducing condition CO, only part of the Eu3 ions was reduced to Eu2 . The existence of trivalent and divalent europium ions was confirmed by photoluminescent spectra. The different valence-change behaviors of europium ions in the hosts were attributed to the difference in host crystal structures. The higher the crystal structure stiffness, the easier the reduction process from Eu3 to Eu2 .     

Long Lasting Phosphorescence in Eu2+ and Ce3+ Co-Doped Strontium Borate Glasses

Long lasting phosphorescence (LLP) was observed in Eu2+, Ce3+ co-doped strontium borate glasses prepared under the reducing atmosphere due to the emission of both Eu2+ and Ce3+. The methods of photoluminescence, thermoluminescence and phosphorescence were used to study the samples, and possible mechanism was suggested. The co-doping of Ce3+ ions poisoned the phosphorescence emission of Eu2+ because of the competition to obtain the trapped electron. The phosphorescence of Ce3+ in the sample decays more quickly than that of Eu2+, which is suggested for the reason that the emission energy of Ce3+ is higher or the distance between Ce3+ and electron traps of the glasses is longer.     

Effects of SrO／Al2O3 Molar Ratio on the Luminescent Characteristics of Rare—Earth Strontium Aluminate Phosphors

The study on the effects of SrO/Al2O3molar ratio on the crystalline phases and photoluminescence characteistics of strontium aluminate phosphors co-activated with Eu^2 andDy^3 were conductde by X-ray powder diffractometry ,fluorescence spectrometer and photometer.The strontium aluminate luminescent materials with different Sro/Al2O3molar ratio emit the visible lights with different color tone after removal of excitation.The peak wavelengths of the emission spectra drift in the direction of short wave,the quantity of Sr4A114O25crystalline phase molar ratio is near 1,the photoluminescence materials have high luminescent intensity,and when it is near0.75,they have long afterglow time.However,when SrO/Al2O3molar ratio is more than1,the luminescent materials appear strong alkaline in water solution;when SrO/Al2O3molar ratio is much less than 0.75,the samples need a higher temperature to be sintered.     

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。     

吡嗪─2─羧酸─乙醇体系导数荧光法同时测定钐、铕、铽、镝

研究了各种有机溶剂对Ｅｕ３＋、Ｔｂ３＋－吡嗪－２－羧酸荧光体系的增敏效应。结果发现：乙醇不仅能使Ｅｕ３＋,Ｔｂ３＋的特征荧光增敏,而且也使Ｓｍ３＋,Ｄｙ３＋的荧光增敏。在ｐＨ６．０,９９．６％乙醇浓度体系中,Ｅｕ３＋,Ｔｂ３＋的荧光强度分别提高４７和１４倍,实现了同时测定Ｓｍ３＋,Ｅｕ３＋,Ｔｂ３＋,Ｄｙ３＋四种离子。本方法已成功地应用于混合稀土氧化物中四者含量的测定。     

室温固相法合成苯甲酸铕与苯甲酸铽荧光粉

以稀土氯化物、苯甲酸、六次甲基四胺为原料,采用固相反应法合成苯甲酸铕与苯甲酸铽配合物。TG-DTA数据显示,六次甲基四胺盐在200℃左右发生热分解;FT-IR、PL测试结果表明,加入六次甲基四胺后,苯甲酸转化成羧酸盐,与稀土离子形成稳定的配合物,合成配合物具有理想的光致荧光性能。     

Synthesis and Characterization of Europium Doped Ceria

Europium doped CeO₂ was synthesized via combustion synthesis method. The powders were found to be in a single phase. The average crystallite size was found to be about 30nm. It was revealed from photoluminescence spectra that there was an excitation band around 368 nm and a narrow excitation peak at 468nm. The emission spectrum showed four peaks at 589, 608, 629 and 650nm.     

Synthesis and Fluorescence of Novel Conjugated Europium Complex

Organicelectroluminescence (OEL)hasbeenstudiedextensivelyforitslowdrivevoltage ,suitabilityforintegratedcircuitandpotentialapplicationforlargeflatpaneldisplay[1,2 ] .GreenandblueluminescentmaterialsforOELdeviceshavebeenbasicallysatisfiedforOELapplication[3 ] .Toourknowledge ,searchfornovel ,stable ,strongredluminescentmaterialsisur gentforapplicationofOELdevicesatthepresenttime .Becausesomelanthanideions ,e .g .,Eu3 + andTb3 + ,possessgoodluminescencecharacteristics (highcolorpurity)base…