Inter- and intraconfigurational luminescence of Er 3+ ions in BaY 2 F 8 under VUV excitation

Using energy- and time-resolved spectroscopy the luminescence properties of Er 3+ doped BaY 2 F 8 crystals were investigated at 10 v K under VUV synchrotron radiation excitation. Radiative intraconfigurational f - f and interconfigurational d - f transitions in Er 3+ ions were observed under f - d excitation. Whereas the onset of 4 S 3/2 population via f - d excitation starts at 59 900 v cm m 1 , efficient excitation of emissions arising from the 2 P 3/2 state begins only above 67 000 v cm m 1 in VUV region. Such behaviour can be explained by a cross-relaxation process of the type ( 2 F(2) 5/2 , 4 I 15/2 ) M ( 2 P 3/2 , 2 P 3/2 ) taking place within f -states of Er 3+ ions finally populating the emitting 2 P 3/2 state.     

Optical spectroscopy of Ce 3+ ions in BaY 2 F 8 single crystals

In the present work we report on the spectroscopic properties of the Ce 3+ ion in BaY 2 F 8 single crystals. The absorption and excitation spectra of the emission centered at 340 v nm have been measured in the temperature range 15-300 v K. The 340 v nm emission consists of two broad partially overlapping bands, peaking at 324 and 347 v nm (at 15 v K), respectively. The full width at half maximum is about 0.5 v eV at room temperature. The absorption spectrum of the lowest in energy component of the f M d transition of Ce 3+ reveals at low temperature a marked vibronic structure. High resolution (0.02 v cm m 1 ) Fourier transform infrared spectroscopy in the wave number range 500-5000 v cm m 1 and in the temperature range 9-300 v K has been exploited to monitor the f level splitting. The absorption transitions from the three Stark components of the 2 F 5/2 manifold to the four of the 2 F 7/2 one, have been monitored in the wave number range 2000-3400 v cm m 1 . The wave number separation at 9 v K between the lowest level of the ground 2 F 5/2 manifold and lowest one of the 2 F 7/2 manifold is found to be 2197.47 v cm m 1 in good agreement with the splitting detected between the two components of the d M f emission.     

(REO)3BO3(RE=La、Gd、Y)中Pr3+的光致发光

研究了紫外光激发下,（ＲＥＯ）３ＢＯ３（ＲＥ＝Ｌa、Ｇd、Ｙ）基质中Ｐr＾３＋的光 谱性质;探讨了基质晶格、阳离子半径、Ｐr＾３＋－Ｏ＾２－键的共价性等因素对光谱性 质的影响;分析了Ｐr＾３＋的发光强度随组成变化的规律性及Ｐr＾３＋的＾３Ｐ１→＾３Ｆ２跃迁发射的自身浓度猝灭机理。     

Sm3+在玻璃中的发光以及Sb6+、Ce6+、Gd3+对Sm3+发光性质的影响

本文研究了单掺(Sm3+,Ce3+、Gd3+.Sb3+、双掺(Sm3++Ce3+、Sm3++Gd3+,Sm3++Sb3+)和兰掺(Sm3++Gd3++Ce3+)约四十余种不同玻璃的发射谱和激发谱.探讨了玻璃成份和掺杂离子浓度对Sm3+发光性质的影响以及Ce3+,Gd3+、Sb3+、Ce3++Gd3+对Sm3+的敏化作用。     

赤铁矿和三羟铝石吸附Cu~(2+)的红外光谱研究

应用红外光谱法,研究了不同pH值和Cu2+浓度条件下,合成赤铁矿和三羟铝石吸附Cu2+后表面羟基结构及其特征吸收峰的变化。结果表明:(1)随Cu2+浓度增加,赤铁矿表面H—O—H和OH的变形振动参与了吸附反应,Cu2+强烈地缔结在Fe—O上,形成了Fe—O—(Cu)结构。(2)酸性条件下,H+破坏了赤铁矿表面的O—H结构,NO3-促使弱峰1 131 cm-1的产生。随pH值增大,赤铁矿表面OH-逐渐由伸缩振动转变为变形振动,Fe—OH和Fe3+—O2-结构不断发生改变。(3)三羟铝石对Cu2+的吸附发生在高波位,随Cu2+浓度增大,其表面游离羟基的O—H弯曲振动、水分子的OH-伸缩振动和H—O—H弯曲振动均参与了吸附反应,Al—O基中的Al3+渐被Cu2+取代从而加强了较低波位的振动强度。(4)随pH值增加,三羟铝石Al—OH的弯曲振动和Al—O的伸缩振动逐渐发生着改变,表明吸附Cu2+后,在其表面形成了AlOCu+与AlOCuOH结构。     

KAIF4：Ce,Gd磷光体的荧光特性及能量传递

采用溶液反应和固相反应,分别合成了ＫＡＩＦ４基质化合物及ＫＡＩＦ４：Ｇｄ、ＫＡＩＦ４：Ｃｅ,Ｇｄ等磷光体,研究了它们的光谱特性。结果表明,ＫＡＩＦ４：Ｇｄ无认顷皮或长波紫外辐激发下,均无任何吸收和发射。在ＫＡＩＦ４：Ｃｅ,Ｇｄ中,Ｃｅ＾３＋离子能有效地将能量传递给Ｇｄ＾３＋离子,使Ｇｄ＾３＋产生了特征锐发射,具发射强度很大。但当Ｃｅ＾３＋浓度固定不变,改变Ｇｄ＾３＋的＾６Ｐ１／２→＾８Ｓ７／２发射     

常温0～1GPa压力下重晶石的拉曼光谱研究

利用碳化硅压腔装置研究了高压下重晶石的S-O对称伸缩振动v987和对称弯曲振动v452及v462的拉曼光谱变化特征.实验结果表明:在常温和0～1GPa压力范围内重晶石稳定,其拉曼谱峰随压力升高向高波数方向移动,二者的关系表达式分别为:v987=0.004 4p+987.42,v452=0.002 3p+452.6,v462=0.001 8p+462.42,而且伸缩振动受压力的影响比弯曲振动大.重晶石的987 cm-1拉曼谱峰强度约为石英464 cm-1拉曼谱峰的六倍,可作为压腔中良好的压力标定物.实验得到压力与重晶石987 cm-1峰偏移量的关系为:p(MPa)=223.16×(△vp)987-90.35(987 cm-1相似文献   

Exafs studies of LiYF 4 -LiREF 4 solid solutions

In this work we are investigating dopant environments in LiYF 4 -LiREF 4 (RE=rare-earth cations) solid solutions, via EXAFS. The main aims are to identify the local environmental symmetry and the average lattice distortion as a function of the concentration and the type of the RE ion. LiY 1 m x RE x F 4 (RE=Gd or Lu) (0< x <1) single crystals were grown by the Czochralski technique under argon or CF 4 atmosphere, crystal-pulling rates were 0.6-1 v mm/h for <100>-oriented boules, with 8-25 v rpm rotation rates. Most of the crystals were also codoped with 2.7 v mol% of neodymium in the melt. EXAFS measurements were performed in transmission and fluorescence modes in the synchrotron XAS line of the LNLS, Campinas, Brazil, in and above the L III absorption edges of the RE ions. The samples were prepared as powder films, for the transmission mode measurements, and as powder or single crystals for fluorescence mode measurements. The WINXAS program was used for data reduction and fitting, and the FEFF6 package was used for the simulations of the spectra. The EXAFS oscillation curves were obtained by standard procedure.     

铈掺杂高钆镥氧化物玻璃制备和光谱性能

实验中采用高温熔融法制备了一系列高钆镥硼硅酸盐新型玻璃体系样品,研究了这种新型玻璃体系的玻璃形成区,测量了样品的玻璃稳定性和密度。结果表明,玻璃体系的玻璃形成区较广,玻璃稳定性良好（析晶温度与转变温度的差为262 ℃）,且玻璃样品的密度达到5 g/cm3。以此种玻璃体系作为基质掺入Ce3+离子,测量其透过光谱、激发光谱、发射光谱、X射线激发发射光谱以及Gd3+离子的衰减时间。结果表明,玻璃的透过性能适合Ce3+离子的掺杂,并且Gd2O3和Lu2O3对闪烁体发光都具有积极的影响,同时研究了Gd3+离子和Ce3+离子的能量传递机理及最佳能量传递掺杂摩尔比。从玻璃的物理性能和光谱性能考虑,这种闪烁玻璃系统具有广泛应用于高能物理材料中的一定潜力。     

惰性离子(La3+,Y3+,Gd3+)对配合物苯乙酮酸邻菲咯啉铕荧光性能的影响

以苯乙酮酸和邻菲咯啉为配体,不同摩尔比铕和惰性离子(La3 ,Y3 ,Gd3 )为中心离子,合成了系列配合物EuxRE1-xL3phen(RE=La,Y,Gd),测定了其荧光激发光谱和荧光发射光谱,研究了惰性离子(La3 ,Y3 ,Gd3 )对Eu3 荧光性能的影响.结果表明,配合物激发光谱相似,均在350～360 nm范围内出现最大激发,属于配体的吸收峰,在398 nm附近出现弱的激发为Eu3 的吸收峰;系列配合物荧光发射光谱相似,均显示Eu3 离子的特征发射光谱,位于583,595,617,654,703 nm附近出现5组强度不同的发射峰,分别归属为Eu3 的5D0-7F0,5D0-7F1,5D0-7F2,5D0-7F3,5D0-7F4能级跃迁.发射光谱表明,系列配合物中La3 离子对Eu3 的荧光发射峰峰位影响最大,EuxLa1-xL3phen中La3 的摩尔分数为0.7时,Eu3 的5D0-7F2跃迁可改变5.2 nm,而Y3 和Gd3 对Eu3 的荧光发射峰峰位影响较弱,配合物EuxY1-xL3phen和EuxGd1-xL3phen中Eu3 的荧光发射峰位变化较小,最大时仅改变2 nm;发射光谱强度表明,La3 对Eu3 的荧光发射影响最大,EuxLa1-xL3phen中La3 含量为0.7时,可使其相对荧光强度增大2倍以上,对其具有很好的敏化作用.这对人们寻找发光性能好、价格便宜的发光材料提供了理论依据.     

KMgF3:Eu2+晶体中Eu2+的受激发射研究

二价铕离子(Eu2 )在KMgF3晶体中产生窄带线状发射,峰值位于360 nm.依据自身建立的激发态能量损耗模型,预测了4f7(6P7/2)→4f7(8S7/2)跃迁实现受激发射的可能性.采用ASE技术测得了KMgF3:Eu2 晶体360 nm发射的光学增益,得到净光学增益系数g=(11.4±3.2)cm-1,实验证实了理论预测.晶体退火或掺杂敏化离子Gd3 或Ce3 可以改善Eu2 的增益效果.     

Influence of OH groups on 1.5-μm emission of Yb3+/Er3+ co-doped tungsten-tellurite glasses

The Yb3+/Er3+ co-doped TeO2-WO3-ZnO glasses bubbling with different times were prepared. The infrared (IR) transmission spectra, emission spectra and fluorescence lifetime of Er3+ at 1.5μm were measured. The quench effects of OH groups on emission intensity of Er3+ at 1.5μm as well as the relationships between fluorescence decay rate and OH group content were investigated. The constant kOH-Er, which represents the strength of the interactions between Er3+ ions and OH groups, is approximately 17.0 × 10-20cm4/s, and is comparable to that for Er3+ in Yb3+/Er3+ co-doped phosphate glasses.     

磁几何阻挫材料天然绿盐铜矿的中红外和拉曼光谱分析

在室温情况下,利用FTIR光谱仪测得了天然磁几何阻挫材料绿盐铜矿(Atacamite,β-Cu2 (OH)3Cl)的中红外光谱4 000～400 cm-1,同时还通过激光显微拉曼光谱仪获得了它的拉曼光谱4 000～95 cm-1.结合它的晶体结构参数,确认了官能团区4 000～2 500～1 000 cm-1和指纹区1...     

铕、铽-2-噻吩甲酸-2,2''''-联吡啶配合物的合成、表征及荧光性质研究

合成了铕、铽-2-噻吩甲酸的二元配合物和铕、铽-2-噻吩甲酸-2,2'-联吡啶的三元配合物,并对它们进行了元素分析、稀土络合滴定、摩尔电导测定,确定了配合物组成分别为REL3·2H2O及REL3 L'·C2H5OH(RE=Eu,Tb;L=2-噻吩甲酸、L'=2,2'-联吡啶),测定了配体及配合物的IR谱、1H NMR谱及荧光光谱.IR谱和1H NMR谱测定表明,配体2-噻吩甲酸羧基氧、配体邻菲咯啉2个氮原子与稀土离子配位.荧光光谱实验表明,高氯酸铕和高氯酸铽分别与2,2'-联吡啶和2-噻吩甲酸反应形成的三元配合物的荧光明显强于二元配合物.     

VUV-UV-visible luminescence of Nd3+, Er3+ and Tm3+ in LiLuF4 single crystal host

An overlook of absorption and luminescence characteristics of Nd³⁺, Er³⁺ and Tm³⁺ centers in LiLuF₄ single crystal is provided. Single crystal doped with the mentioned RE ions were prepared by micro-pulling-down technique in the form of few cm long rods with the diameter of about 2 mm. Excitation and emission spectra and fast decay kinetics in VUV spectral region were measured at SUPERLUMI station at synchrotron DESY, Hamburg and characterization was further completed in UV-visible region at conventional spectrophotometers. Observed absorption and emission peaks are ascribed to the 5d–4f and 4f–4f optical transitions in the doped rare earth ions. Concentration dependence of the decay kinetics is discussed.     

高色纯度白光LED用蓝光材料Gd2MgTiO6∶Bi^3+的合成及性能

采用高温固相法合成了一系列蓝光荧光粉Gd2-xMgTiO6∶xBi3+(0.0025≤x≤0.015),并对样品的表面形貌、晶体结构、发光性能和热稳定性进行了探究。SEM测试结果显示,样品Gd2MgTiO6∶Bi3+的粒径分布范围大,颗粒尺寸在1~5μm范围。XRD测试表明,Bi3+成功掺杂进入基质Gd2MgTiO6中且无杂相产生。荧光光谱测试结果表明,在375 nm波长激发下,蓝光荧光粉Gd2MgTiO6∶Bi3+于385~500 nm波长范围内呈现出属于Bi3+的1S0→3P1能级跃迁的窄带发射峰,且发射强度最大处位于418 nm,这有利于避免光的重吸收现象。不同掺杂浓度下样品的发射光谱研究表明,最佳Bi3+掺杂浓度为x=0.0075。此外,发光强度最佳的蓝光样品Gd1.9925MgTiO6∶0.0075Bi3+的CIE坐标为(0.1629,0.0364),位于蓝光区域,色纯度高达96.42%,平均荧光寿命高达11.29 ms。样品的热稳定性高于文献报道的同类样品。这些均说明该样品是一种发光性能和热稳定性能良好的W-LEDs用蓝光组分。     

Sr3Gd(PO4)3:Tm3+的真空紫外光谱特性

研究了Sr3Gd(PO4)3 : Tm3 和GdPO4 : Tm3 样品的结构特性、光谱特性.GdPO4 : Tm3 为单斜晶系,基质掺入铥离子后结构没有明显变化.GdPO4:Tm3 在164和210 nm附近有强烈的吸收峰.位于164 nm附近的强烈的吸收峰是归因于基质的吸收引起,210 nm附近的吸收峰则归因于Gd 的8S7/2-6GJ的能级跃迁.在164 nm真空紫外光激发下,样品于453及363 nm处有较强的发射峰,发射主峰位于453nm,属于Tm3 的1D2→3H4(22,123 cm-1)跃迁的典型发射.由于阳离子质量的不同,Sr3Gd(PO4)3:Tm3 在166 nm附近的激发峰高于GdPO4: Tm3 的同位置的激发峰,其在363 nm处的发射有明显减弱,而在453 nm处的蓝色发射有显著的增强.     

Sm~(3+)在玻璃中的发光以及Sb~(6+)、Ce~(6+)、Gd~(3+)对Sm~(3+)发光性质的影响

本文研究了单掺(Sm~(3+),Ce~(3+)、Gd~(3+).Sb~(3+)、双掺(Sm~(3+)+Ce~(3+)、Sm~(3+)+Gd~(3+),Sm~(3+)+Sb~(3+))和兰掺(Sm~(3+)+Gd~(3+)+Ce~(3+))约四十余种不同玻璃的发射谱和激发谱.探讨了玻璃成份和掺杂离子浓度对Sm~(3+)发光性质的影响以及Ce~(3+),Gd~(3+)、Sb~(3+)、Ce~(3+)+Gd~(3+)对Sm~(3+)的敏化作用。     

金属掺杂纳米固体超强酸SO2-4/ZrO2的IR考察

首先采用sol-gel法制备出ZrO(OH)2,再分别用Ni^2 ,Al^3 ,Sn^4 ,Ag^ ,Sn^2 金属盐溶液和H2SO4稀溶液浸渍ZrO(OH)2的方法合成了一系列金属离子掺杂的SO4^2-／ZrO2纳米固体超强酸。并用XRD,TEM和IR技术考察了各样品的性能。结果发现,经不同金属掺杂的SO4^2-／ZrO2颗粒具有固体超强酸的IR谱特征。经NiH,Sn^4 掺杂的样品中Zr-O和S-O键振动吸收峰明显蓝移,Zr-O的vZr-O由SO4^2-／ZrO2的485cm^-1增大到Ni^2 ,Sn^4 掺杂样品的500cm^-1,s=0的vas由1390cm^-1增大到1405和1400cm^-1,而Sn^2 掺杂的样品变化不大。说明Ni^2 ,Sn^4 金属离子的掺杂增强了样品的超强酸性。同时还发现,随着样品焙烧温度的提高,经Ni^2 和Al^3 掺杂的SO4^2-／ZrO2纳米颗粒,Zr-O和S=O键振动吸收峰明显蓝移,而Ag^ 掺杂的样品在焙烧温度达到1073K时IR谱只是吸收强度减弱,振动频率不变。     

偏硅酸钙中Pr3+的4f5d态的光谱特性及Pr3+→Gd3+的能量传递

合成了高效发射UV光的CaSiO3:Pr^3 新型荧光体，研究了室温下Pr^3 的4f5d态的发射和激发光谱，Pr^3 的4f5d态的最低子能级向4f^2组态的^3H4，^3H6和^1G4能级跃迁产生UV发射，并不伴随有4f-4f能级跃迁的可见光发射。Pr^3 的浓度猝灭是由于辐射和无辐射能量传递造成的，同时，在CaSiO3中，存在Pr^3 →Cd^3 的能量传递，探讨了其能量传递特性。