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。     

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.     

The influence of Ba(PO3)2 on the formation characteristics of fluorophosphate glasses

Formation characteristics of glasses in the system AlF3–MF2–Ba(PO3)2 (M=Ca, Mg, Sr, Ba) have been studied as a function of Ba(PO3)2 content. Glass formation tendency increased with increasing Ba(PO3)2. The critical cooling rate, Rc, for glass formation decreased from 98±7 to 2±0.5°C s-1 when the Ba(PO3)2 content of the glass increased from 0 to 1.5 mol%. The improvement in glass formation caused by Ba(PO3)2 was due to linking of the broken chains present in the structure. The infrared transmission spectra of these glasses and their crystallization products suggested that the structure changed from short chains of AlF6 groups to long chains of PO3F and Ba(Ca, Mg, Sr)P2O7 groups with increasing Ba(PO3)2 content of the glass.     

Devitrification of TeO2-doped Fluoroaluminate Glass

Crystallization behavior of the glass system AlF3-MgF2-CaF2-SrF2-BaF2-YFa-TeO2 （AMCSBY-TeO2） was studied by the nonisothermal method using differential thermal analysis. The activation energy E and Avrami exponent g were determined by nonisothermal method. It is found that the value of E varies with increasing TeO2 and reaches a minimum at 10 mol fraction TeO2, while g decreases from 3.65 to 1.78 with the addition of TeO2. X-ray diffraction shows that Ba2TeaOs, MgTe205, and SrTeOa phase formed when the glasses were reheated. The addition of TeO2 changes the crystallization mechanism and improves the stability of the fluoroaluminate glass.     

掺Er3+碲酸盐玻璃光谱性质和热稳定性的提高研究

用高温熔融法制备了摩尔组分百分比为70TeO2-20(ZnO、WO3,AlO1.5)-9NaO0.5-1ErO1.5的碲酸盐玻璃样品.测量了玻璃样品的吸收光谱和荧光光谱,用差热分析方法(DTA)测试了玻璃的热稳定性.结合Judd-Ofelt理论和McCumber理论分别计算得到了三种玻璃样品的强度参数Ω1(t=2,4,...     

TeO2-Nb2O5系统玻璃的成玻性能研究

TeO2是一种线性和非线性光学性能优良、但无法单独形成玻璃的重金属氧化物玻璃系统,Nb2O5的引入有利于获得均匀而稳定的碲酸盐系统玻璃.研究发现,Nb2O5的引入会改变TeO2-Nb2O5系统玻璃中Te4 、Nb5 的配位数,进而对玻璃的结构和成玻能力、稳定性以及析晶性能均产生明显的影响.含有20-30wt%Nb2O5的碲酸盐系统玻璃表现出较好的综合品质.     

Raman Spectrum and Thermal Stability of a Newly Developed TeO2-BaO-BaF2-La2O3-LaF3 Glass

In this work, a new TeO2-BaO-BaF2-La2O3-LaF3 oxyfluorotellurite glass system is investigated. Differential thermal analysis (DTA) and structural analysis by Raman scattering spectra are reported on the glasses. The DTA results indicated that an increase of fluoride content in the glasses decreases the glass transition temperature (Tg) and increases the crystallization onset temperature (Tx). As a result the 70TeO2·20BaF2·10LaF3 glass showed a large Hruby's parameter, possessing excellent thermal stability. Changes in glass network structure with fluoride content are discussed based on the Raman scattering spectra of glasses. The glass network structures in the 70TeO2·(20-x)BaO·xBaF2·(10-y)La2O3·y1 aF3 glasses are basically composed of both Te(O, F)4 and Te(O, F)3 units, but the Te(O, F)4/Te(O, F)3 ratio in the glass becomes higher with increasing fluoride content. This may be considered one of the reasons why the 70TeO2·20BaF2·10LaF3 glass exhibits excellent thermal stability.     

TeO_2-Nb_2O_5-BaO-BaCl_2系统玻璃结构及银纳米晶引入研究

碲酸盐氧卤玻璃具有低声子能以及较好的稳定性和析晶性能等优秀的综合品质,是一类很有前途的光学玻璃材料。采用熔融法制备了不同组成的TeO2-Nb2O5-BaO-BaCl2系统玻璃,研究了网络结构变化和组成对该系统玻璃的成玻璃性能和析晶性能的影响,同时探讨了向玻璃基体内引入银纳米晶体的可能性。结果表明,BaCl2的引入使得玻璃网络结构中键合及基团种类增多,碲氧链间的连接加强,网络结构更加紧密,并且成玻璃区域有所扩展。TeO2-Nb2O5-BaO-BaCl2系统玻璃基体在保持自身结构稳定性的同时,更有利于AgCl纳米晶体析出,是一种适合金属纳米晶掺杂的优良光学玻璃基体材料。     

Crystallization kinetics of fluorophosphate glasses: Part I Effect of composition and heating rate

Crystallization behaviour of glasses from the system AlF3-MF2-Ba(PO3)2 (M=Ca, Mg, Sr, Ba) have been studied using differential thermal analysis as a function of Ba(PO3)2. The kinetic parameters for crystallization, namely, the activation energy, E, frequency factor, ν, and Avrami exponent, n, were determined. E, ν and n decreased with increasing Ba(PO3)2. Crystallization commenced at higher temperatures and the crystal growth mechanism changed from bulk to surface with increasing Ba(PO3)2. X-ray diffraction analysis revealed that CaAlF5, SrAlF5, CaAlF7 and CaSrAlF7 crystallize from these glasses when heated. The infrared transmission spectra indicated that AlF6, PO3F and Ba(Ca,Mg,Sr)P2O7 groups were present in these glasses. This revised version was published online in November 2006 with corrections to the Cover Date.     

Etude des verres fluores dans les quaternaires ZnF2ThF4AlF3MF2 (M = Mg,Ca, Sr,Ba)

Fluoride glasses have been investigated in the ZnF₂AlF₃ThF₄MF₂ (M = Ba, Sr, Ca, Mg) systems. The vitreous areas are given for the basic ternary diagrams and at a constant 40 % ZnF₂ content. Small samples may be prepared for the compositions: 40 % ZnF₂, 20 % AlF₃, 20 % ThF₄, 20 % MF₂ (M = Ba, Sr, Ca). The glassy transition occurs between 310° C and 350° C and the fusion between 650° C and 750° C. The optical transmission range lies from 240 nm to 7500 nm. The average values of refractive index, thermal expansion coefficient and density are: n_D ～ 1.48, α ～ 15.10^?6° K^?1d ～ 5. The high compactness of the anion array is compared to that of close-packed crystalline fluorides.     

掺铒碲酸盐玻璃的热力学稳定性和光谱性质的研究

分析了掺Er³⁺碲酸盐玻璃的热力学稳定性能,研究了掺Er3+碲酸盐玻璃的吸收和荧光光谱性质;应用Judd-Ofelt理论计算了碲酸盐玻璃中Er3+离子的强度参数Ω(Ω₂=4.79×10^-20cm², Ω₄=1.52×10^-20cm²,Ω₆=0.66×10^-20_cm2),计算了离子的自发跃迁几率,荧光分支比;应用McCumber理论计算了Er3+的受激发射截面(σ_e=10.40×10^-21cm²)、Er³⁺离子⁴I_13/2→⁴I_15/2 发射谱的荧光半高宽(FWHM=65.5nm)及各能级的荧光寿命(⁴I_13/2能级为τ_rad=3.99ms);比较了不同基质玻璃中Er3+离子的光谱特性,结果表明掺铒碲酸盐玻璃更适合于掺Er³⁺光纤放大器实现宽带和高增益放大.     

Effects of GeO2 on the thermal stability and optical properties of Er/Yb-codoped oxyfluoride tellurite glasses

The aim of this article was to study the influence of GeO₂ on the thermal stability and optical properties of Er³⁺/Yb³⁺ codoped (70 − x)TeO₂–xGeO₂–PbF₂–BaF₂ (TGEYx) glasses prepared by using a melting method. The properties of Er³⁺/Yb³⁺ codoped glasses were investigated by using differential scanning calorimetry, upconversion luminescence, Raman and optical absorption spectra. The results indicated that TGEY35 glass with the germanate–tellurite mixed network showed the best thermal stability and poor crystallization tendency. With increasing the GeO₂ content, the maximum phonon energy of oxyfluoride tellurite glass network increased, while the phonon density decreased. The upconversion emission intensities enhanced obviously based on the decreasing phonon density of glass hosts, while the increasing red emission (657 nm) with the increase of GeO₂ concentration was attributed to the relative larger maximum phonon energy which matching the energy gap between the pertinent ⁴S_3/2 and ⁴F_9/2 levels.     

WO3/Nb2O5掺杂对碲酸盐玻璃热学性质和拉曼光谱特性的影响

报道了钨碲酸盐玻璃系统TeO₂-ZnO-Na₂O-WO₃ 和钨铌碲酸盐玻璃系统TeO₂- ZnO-Na₂O-Nb₂O₅-WO₃抗析晶热稳定性和拉曼光谱特性. 实验研究了掺杂WO₃和Nb₂O₅对碲酸盐玻璃抗析晶热稳定性和拉曼光谱特性的影响, 并分析讨论了掺杂碲酸盐玻璃拉曼谱带展宽机制. 结果表明, 掺杂WO₃和Nb₂O₅较大地提高了碲酸盐玻璃的抗析晶热稳定性, 钨铌碲酸盐玻璃最大抗析晶热稳定性ΔT达154℃. 拉曼光谱研究表明,WO₃和Nb₂O₅的加入使碲酸盐玻璃在921和862cm^-1附近出现特征谱带, 导致拉曼光谱中高频移区从550cm^-1延伸扩展到950cm^-1, 从而有效地拓宽了碲酸盐玻璃的拉曼带宽, 钨铌碲酸盐玻璃最大拉曼光谱半高宽可达355cm^-1. 实验研究表明,钨铌碲酸盐玻璃是宽带拉曼光纤放大器的候选材料之一.     

1.3 μm Emission from Nd3+-doped Tellurite Glass Fiber

1 wt pct Nd2O3-doped tellurite bulk glass and fiber with the same composition of 75TeO2-15ZnO-5Na2O-5Li2O (molfraction, %) were fabricated. Judd-Ofelt analysis was carried out for the bulk. The emission from the 4F3/2→4I13/2 transition in fiber is at 1.33 μm wavelength with a spectral bandwidth of 55 nm, which is similar to that in bulk. In the case of the fiber, the lifetime of 4F3/2 level is 164μs, and the quantum efficiency is ～100%. The figure-of-merit for gain (σoT0) for Nd3 -doped tellurite glass is about 2.8×10-24 cm2.s, which is quite comparable with that in Nd3 -doped fluoroaluminate glasses, and is an order of magnitude larger than pr3 -doped fluoride glasses.     

Effect of CdF2 addition on thermal stability and upconversion luminescence properties in Tm–Yb codoped oxyfluoride silicate glasses

Tm³⁺–Yb³⁺ codoped oxyfluoride silicate glasses suitable for upconversion laser has been fabricated. In this paper, effect of CdF₂ addition on thermal stability and upconversion luminescence properties in Tm³⁺–Yb³⁺ codoped oxyfluoride silicate glasses have been systematically investigated. The experimental results indicate that, with the substitution CdF₂ for PbF₂, the glass thermal stability increases and the UV cutoff edge moves to short-wave band slightly. With increasing CdF₂ content, the blue and red upconversion luminescence intensity increases slightly at first, and then increases rapidly. While the near infrared (NIR) upconversion emission intensity increases notably at first and then increases slightly. However, the blue and NIR luminescence intensity are much stronger than that of red, indicating these oxyfluoride silicate glasses are more preferable for blue and NIR emissions than red emission. The possible upconversion mechanisms for the blue, red and NIR fluorescence are also estimated and evaluated.     

Nouveaux verres fluores dans les systems AF2 - MF2 - MF3New fluoride glasses in the AF2-MF2-MF3

Glass formation has been investigated in ternary systems AF₂ - BF₂ - MF₃ with A = Pb, Ba ; B = Mn, Zn, Cd, Sn, Ba ; M = Fe, Ca, In. Twelve new fluoride glasses systems are shown. The most stable glasses are obtained in the PbF₂ - BaF₂ - InF₃ system with characteristic temperatures : Tg = 250°C, Tc = 318°C and Tf = 588°C for 30 PbF₂ - 20 BaF₂ - 50 InF₃, the refractive index is n_D = 1.5492 and the glasses are transparent up to 8.2 μm.The study of PbF₂ - MF₂ - FeF₃ glassy systems with M = Mg, Ca, Sr, Ba confirms the network former behavior of octaedrally coordinated 3d transition metal ions.     

Synthesis,structural, thermal and optical properties of TeO2–Bi2O3–GeO2–Li2O glasses

In this study, synthesis and characterization of novel quaternary tellurite glass system TeO₂–Bi₂O₃–GeO₂–Li₂O is presented. The compositions include TeO₂ and GeO₂ as glass formers while different proportion of Bi₂O₃ and Li₂O act as network modifiers. Differential thermal analysis, X-ray diffraction, scanning electron microscopy energy dispersive X-ray spectroscopy, laser ablation inductively coupled plasma mass spectrometry, UV–Vis and Raman spectroscopy are applied to study the structural, thermal and optical properties of the studied glasses. Obtained glasses possess a relatively low glass transition temperature (around 300 °C) if compared to other tellurite glasses, show good thermal transparency in the visible and near infra-red (from 2.4 to 0.4 μm) and can double the frequency of laser light from its original wavelength of 1064 nm to its second-harmonic at 532 nm (i.e. second harmonic generation).     

Intense red upconversion emission of Yb/Tm/Ho triply-doped tellurite glasses

By conventional melting and quenching methods, 3Yb2O3-0.2Tm2O3-xHo2O3 (wt%, x=0.2~1.2) was doped into an easily fiberized tellurite glass with composition of 78TeO2-10ZnO-12Na2O (mol%) to form YTH-TZN78 glasses. Under 976 nm excitation, the direct sensitizing effect of Yb ions (Yb→Ho) and indirect sensitizing and self-depopulating effects of Tm ions (Yb→Tm→Ho) were found to present intense red upconversion emission at 657 nm (Red, Ho:5F5→5I8) and were responsible for the absence of the usually observed 484 nm emission (Blue, Tm:1G4→3H36). Regardless of the dopant concentration of Ho ions, the intensity of the red emission at 657 nm (Red, Ho:5F5→5I8) is about three times stronger than that of the green one at 543 nm (Green, Ho:5S2→5I8). For this certain red emission at 657 nm, 0.4 wt% Ho2O3-doped YTH-TZN78 glass was found to present the highest emission intensity and is therefore determined as a promising active tellurite glass for red fiber laser development.     

Refractive-index patterning of tellurite glass surfaces by laser spot heating

A dot pattern of a refractive-index change was formed by spot heating with laser-beam irradiation on sodium tellurite glasses. The 15Na(2)O . 85TeO(2) (mol. %) glass doped with 2 mol. % of CoO was irradiated by a green light-beam spot (532 nm) ~800 mum in diameter from the second-harmonic generator of a Q-switched pulsed YAG laser. The map of the refractive index of the glass was determined with an He-Ne laser beam by a scanning ellipsometric technique at a resolution of 100 mum x 50 mum, indicating that the spots possessing a refractive index lower by ~0.05 were formed at the region irradiated by the laser beam.     

Structural variations in layered alkaline earth metal cyclohexyl phosphonates

Two series of alkaline earth metal cyclohexyl phosphonates, M(C₆H₁₁PO₃H)₂(H₂O) (M = Ca, Sr and Ba) (1–3) and M(C₆H₁₁PO₃)(H₂O) (M = Mg, Ca, Sr, and Ba) (4–7) have been synthesized under mild reaction conditions. All new compounds have been characterized using elemental analysis, IR, TGA and powder X-ray diffraction techniques. The molecular structure of compound 2 determined using single crystal X-ray diffraction technique reveals a layered polymeric structure.