MF2(M=Mg,Ca,Zn,Sr,Ba)对掺Yb3+磷酸盐玻璃性质的影响

熔制了60P2O5.6Al2O3@(33-x)BaO.xBaF2.1Yb2O3(x=0,3,6,9)和60P2O5.6Al2O3.27BaO@6MF2.1Yb2O3(M=Mg、Ca、Sr、Zn、Ba)(分子分数)玻璃,测试了其折射率、密度、转变温度、析晶温度、熔点温度、红外光谱和紫外吸收光谱,讨论了二价氟化物MF2(M=Mg、Ca、Sr、Zn、Ba)对磷酸盐玻璃热稳定性及内部结构的影响,测试了Yb3+离子的吸收光谱、荧光光谱、荧光寿命,计算了光谱参数,讨论了MF2对Yb3+磷酸盐玻璃光谱性质的影响.结果表明二价金属氟化物是作为网络外体进入到磷酸盐玻璃结构中,并没有改变磷酸盐玻璃内部的[PO4]链状结构,二价金属氟化物还有助于提高Yb3+离子的受激发射截面,和自发辐射几率,荧光半高宽.     

M3MgSi2O8(M=Sr,Ba)中Ce3+的发光性质

本文合成了掺Ce3 的M3MgSi2O8（M＝Sr,Ba）荧光粉,这两种荧光粉在UV光激发下发射出较强的蓝紫色光,报道了它们室温下的激发光谱和发射光谱以及77K低温下的荧光光谱．阐述了在这两种焦硅酸盐体系中,Ce3 均形成两个发光中心,且随Sr,Ba顺序,荧光体发射峰稍稍向短波移动．     

磷酸盐激光玻璃中杂质离子铁和铜对激光效率的影响

实验研究了Fe和Cu离子对N31型激光玻璃在激光波段1053 nm激光斜率效率的影响。研究发现, 随着Fe离子含量的增加, 激光斜率效率呈e指数快速下降, 激光阈值呈二次方程形式快速增加, 并得出Fe离子含量与斜率效率和激光阈值之间的经验关系式。同时发现, 在相同掺杂浓度条件下, Cu离子比Fe离子更加严重地降低钕玻璃的激光性能。研究结果对如何提高激光玻璃的增益性能和定量控制原材料的杂质含量具有一定指导意义。     

(Ba,Mg,Sr)O·nAl2O3:M(n=4.6,M=Ce,Tb)的合成及发光性质研究

采用高温固相反应合成(Ba,Mg,Sr)O·nAl2O3M(n=4.6,M=Ce,Tb)发光材料.经X射线衍射分析,属六方晶系,与JSPDS标准卡完全一致.用同步辐射实验室真空紫外光谱站设备进行了光谱分析,在(Ba,Mg,Sr)O·nAl2O3Ce(n=4.6)的激发光谱中,产生160nm和260nm的激发峰,分别由基质和铈离子的吸收引起的.在(Ba,Mg,Sr)O·nAl2O3Tb(n=4.6)的激发光谱中,产生160、190和234nm的激发峰,其中160nm和234nm的激发峰是宽带峰,分别是由基质吸收和铽离子的4f-5d吸收引起的;190nm峰是铽离子的特征吸收引起的.由于铽离子的特征吸收和基质吸收产生较大的交迭,因此基质对铽离子具有能量传递.     

碱金属和碱土金属对掺Tm3+碲酸盐玻璃光谱性质的影响

研究了碱金属和碱土金属离子修饰的掺铥碲酸盐玻璃的光谱性质,讨论了碱金属和碱土金属对掺铥碲酸盐玻璃J-O强度参数、1.46μm荧光发射强度、荧光半高宽、受激发射截面等光谱性质的影响,并与一些传统氧化物玻璃进行了比较.研究表明碱金属Li 和碱土金属Ba2 掺碲酸盐玻璃更适宜用作掺铥光放大器基质.含Li 的碲酸盐玻璃展现出7.90×10-21cm2的高发射截面;含Ba2 碲酸盐玻璃具有7.55×10-21cm2的高发射截面、103nm的荧光半高宽.     

Solvothermal synthesis of well-dispersed MF(2) (M = Ca,Sr,Ba) nanocrystals and their optical properties

MF(2)?(M = Ca,Sr,Ba) nanocrystals (NCs) were synthesized via a solvothermal process in the presence of oleic acid and characterized by x-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectra, UV/vis absorption spectra, photoluminescence (PL) excitation and emission spectra, and lifetimes, respectively. In the synthetic process, oleic acid as a surfactant played a crucial role in confining the growth and solubility of the MF(2) NCs. The as-prepared CaF(2), SrF(2) and BaF(2) NCs present morphologies of truncated octahedron, cube and sheet in a narrow distribution, respectively. Possible growth mechanisms were proposed to explain these results. The as-prepared NCs are highly crystalline and can be well dispersed in cyclohexane to form stable and clear colloidal solutions, which demonstrate strong emission bands centred at 400?nm in photoluminescence (PL) spectra compared with the cyclohexane solvent. The PL properties of the colloidal solutions of the as-prepared NCs can be ascribed to the trap states of surface defects.     

用于微片激光器的Nd~(3 )掺杂四磷酸盐玻璃光谱研究

制备了Ｎd３＋掺杂四磷酸盐玻璃,测量了吸收光谱、荧光光谱,计算Ｎｄ３＋的发射截面,研究了其荧光特性、浓度猝灭及其机制、以及ＯＨ基对荧光强度和能量传递的影响,研究发现在四磷酸盐玻璃 Ｎｄ３＋的最佳浓度约为 ４．１×１０２０ ｉｏｎｓ／ｃｍ３,在研究光谱性质的基础上实现了Ｎｄ３＋掺杂四磷酸盐玻璃微片激光器１．０５４μｍ的连续激光输出．     

Ce3+对磷酸盐闪烁玻璃耐辐射性能的影响

研究了空气气氛下制备的掺Ce3+磷酸盐闪烁玻璃.XPS分析结果显示,玻璃网络结构中的铈离子以低化合价(三价)形式存在.分别测试了含Ce3+及不含Ce3+玻璃样品在辐射前及经特定剂量辐射后的紫外可见透过光谱.实验结果表明,含Ce3+玻璃在大于390nm波长处的辐射诱导吸收带消失或明显减弱.通过计算样品的辐射诱导吸收系数μ发现Ce3+离子的引入有效提高了磷酸盐闪烁玻璃的抗辐射能力.     

伽马辐照对掺镱硅酸盐玻璃光学性能的影响

采用传统的高温熔融法熔制了一系列掺镱硅酸盐玻璃, 并测试了这些样品经总剂量为5 kGy的钴-60伽马射线辐射源辐照前后的吸收谱、荧光谱和上转换发光光谱. 实验结果表明: 辐致暗化效应导致玻璃样品在400 nm附近出现一个非常强的宽吸收带, 其尾端可延伸至近红外区.经辐致损耗谱分析可知, 部分Yb³⁺离子在辐照过程中通过俘获电离自由电子转变成了Yb²⁺离子, 导致掺杂样品的辐致损耗明显比基质材料的要大. 在960 nm LD泵浦下辐照过的样品荧光强度、上转换发光强度及荧光寿命均有所下降, 且在476 nm附近出现了氧缺陷ODC(Ⅱ)的荧光.室温下辐照过的样品在荧光测试过程中温度明显升高并出现漂白现象.     

OH- 对 Tm3+/Yb3+ 共掺碲酸盐玻璃上转换发光的影响

研究了Tm3 /Yb3 共掺碲酸盐玻璃的Raman光谱、红外光谱和上转换发光光谱,分析了OH-对Tm3 上转换发光的影响。结果表明,氧氯碲酸盐玻璃的声子能量高于氧氟碲酸盐玻璃的声子能量,但是Tm3 /Yb3 共掺氧氟碲酸盐玻璃的上转换发光强度高于Tm3 /Yb3 共掺氧氯碲酸盐玻璃。分析认为这主要是由于OH-的影响,在氧氟碲酸盐玻璃中OH-的浓度较低,导致Tm3 的荧光寿命高,从而提高Tm3 的上转换发光。在一定程度上,OH-对Tm3 上转换发光的影响大于声子能量对Tm3 上转换发光的影响。研究结果有助于进一步提高Tm3 的发光效率。     

Influence of MO/MF2 modifiers (M = Ca,Sr, Ba) on spectroscopic properties of Eu3+ ions in germanate and borate glasses

Series of Eu³⁺-doped lead-free germanate and borate glasses were synthesized. The MO glass modifiers (M = Ca, Sr or Ba) were partially or totally substituted by MF₂ in chemical composition. In contrast to samples modified by CaO/CaF₂ or SrO/SrF₂, the germanate glass samples containing BaO and/or BaF₂ are fully amorphous, while the lead-free borate glasses are fully amorphous, independently from glass modifiers. Effect of glass modifiers on spectroscopic properties of Eu³⁺ were systematically investigated.For that reason, excitation and emission spectra of Eu³⁺ ions in examined systems were registered. Based on the emission spectra, ratio of integrated luminescence intensity of the ⁵D₀ → ⁷F₂ transition to that of the ⁵D₀ → ⁷F₁ transition (R factor) was calculated. Moreover, the luminescence decay curves were collected and the luminescence lifetimes of the ⁵D₀ excited state of Eu³⁺ ions were determined in function of MF₂ concentration.     

Physicochemical properties of La(Ba,M)CuFeO5+δ (M = Sr, Ca, Mg) solid solutions

The crystal structure of LaBa_1?x M_xCuFeO_5+δ (M = Sr, Ca, Mg; 0 < x ≤ 0.5) solid solutions has been studied by x-ray diffraction and IR absorption spectroscopy, and their thermal stability, thermal expansion, and electrical conductivity have been determined in air between 290 and 1270 K. The structure of LaBa_1?x Sr_xCuFeO_5+δ has been shown to change from cubic to tetragonal at x ? 0.4?0.45, whereas the LaBa_1?x M_xCuFeO_5+δ (M = Ca, Mg) solid solutions have a cubic structure up to x = 0.5. The composition dependences of structural parameters and physicochemical properties for LaBa_1?x Sr_xCuFeO_5+δ show anomalies at x = 0.25, which suggests ordering of the La³⁺, Ba²⁺, and Sr²⁺ cations in the structure of La(Ba,Sr)CuFeO_5+δ, leading to the formation of a new chemical compound, LaBa_3/4Sr_1/4CuFeO_5+δ.     

Yb3+掺杂SiO2-Bi2O3-B2O3玻璃的物理性质及光谱性质

选取玻璃组分60SiO₂-xBi₂O₃-(30-x)B₂O₃-2K₂O-7Na₂O-1Yb₂O₃(以mol％记,x=0,5,10,15,20,25,30)为研究对象。通过测试试样的物理性质和光谱性质,应用倒易法(reciprocity method)计算Yb³⁺离子的受激发射截面(σ_emi),并且计算了Yb³⁺的自发辐射几率(A_rad),²F_5/2能级的辐射寿命(T_rad)。讨论了玻璃中Bi₂O₃和B₂O₃的组成变化对其物理性质、Yb³⁺离子的吸收特性、发光特性以及OH^-离子对实测Yb³⁺荧光寿命(T_f)的影响。结果表明:Yb³⁺掺杂的Si₂-Bi₂O₃-B₂O₃具有较好的光谱性能,是一种新型的Yb³⁺掺杂双包层光纤候选基质材料。     

Synthesis and Physical Properties of (Cu,M)Ba2Ca3Cu4Oz (M=C,Mg,Ni,Al,Zn,Tl)

We have synthesized the single phase samples of Cu _x C _0.1 Ba ₂ Ca ₃ Cu ₄ O _z (x=0.20.9). Transport and magnetic measurements and iodometric titration analysis were carried out for these materials. From these results we discuss the correlation between T _c , the Hall number, copper valence and oxygen content. The effect of the substituted M ions on T _c in (CuC, M)-l234 (M=Ni,Zn,Al,TI,Mg) is also discussed. We propose a unique selective carrier-doping mechanism in (Cu,C)- and (CuC,Mg)-1234 systems.     

掺铒磷酸盐玻璃反应气氛法除水的研究

制备了不同含水量的掺铒磷酸盐玻璃，研究了各种工艺参数对反应气氛法除水效果的影响。结果表明由鼓泡气体带入的除水剂是玻璃除水的主要动力；在通气最初阶段的除水速率最快，并且提高除水温度、增大通气流量均有助于提高除水效率；结合实验从反应热力学角度讨论了除水机理，并指出在玻璃熔体中除水反应受熔体“笼效应”影响，反应速率大小取决于OH与CCl4形成偶遇对概率的大小。     

Thermochemistry and thermal characteristics of Ba2MIIUO6 (MII = Mg, Ca, Sr, Ba)

A series of uranium compounds with the composition Ba₂M^IIUO₆ (M^II = Mg, Ca, Sr, Ba) were synthesized by a solid-phase procedure. The polymorphism for Ba₂SrUO₆ was studied by high-temperature X-ray diffraction, and the coefficients of thermal expansion were determined. The standard enthalpies of formation of crystalline Ba₂M^IIUO₆ at 298.15 K were determined by the reaction calorimetry.     

Lumine scence of Ce3+ and Tb3+ in M3(PO4)2 (M = Sr,Ba)

The luminescence properties of Ce³⁺- and Tb³⁺-activated M₃(PO₄)₂ (M = Sr,Ba) are reported. It is shown that only a small part (⩽ 0.3%) of the M2+ ions can be replaced by Ln³⁺ ions. At higher concentrations a second phase, M₃Ln(PO₄)₃, is formed. The luminescence properties are due to these two different phases.     

几种重金属氧化物和GeO2的加入对掺Yb3+氟磷玻璃的光谱和激光性能的影响

实验对比研究了Ga₂O₅、TeO₂、GeO₂、WO₃、Nb₂O₅和Bi₂O₅金属氧化物的掺入对氟磷激光玻璃的光谱和激光性能的影响。结果表明, TeO₂、GeO₂和Ga₂O₅的加入增大了Yb³⁺的吸收和发射截面; 其中, 掺有TeO₂的氟磷玻璃的Yb³⁺吸收和发射截面最大, 分别达到了1.95 pm²和0.85 pm²。Ga₂O₅、Nb₂O₅和GeO₂的加入对玻璃激光性能的提高具有极大的帮助; 其中, 在掺有Ga₂O₅的氟磷玻璃中激光参数SFL值最大, 为1.237。同时发现, 在TeO₂和GeO₂掺杂氟磷玻璃中也存在严重的Yb³⁺荧光俘获现象, 大大减弱了其激光性能。