铒硼硅酸盐玻璃结构的研究

通过对Er2O3-Al2O3-B2O3-SiO2玻璃红外光谱和激光拉曼光谱的分析表明,该系统玻璃中存在[SiO4][、BO3][、BO4][、AlO4][、AlO6]等基团。同时对玻璃进行析晶热处理,热处理后析晶产物为ErBO3相,表明稀土玻璃中的Er3+主要偏聚在富硼相中,在受热过程中发生了分相,并以ErBO3相的形式析出,富硅相则保持玻璃态。将稀土玻璃结构与析晶产物联系起来研究,在一定程度上可以揭示稀土玻璃的结构形式,根据研究结果提出了Er2O3-Al2O3-B2O3-SiO2玻璃的结构模型。     

Eu~(3+)/Tb~(3+)掺杂硼硅酸盐玻璃的发光性能

为了弥补目前白光LED显色指数的不足,用传统熔融法制备了Eu3+/Tb3+掺杂的硼硅酸盐玻璃,研究了Eu3+/Tb3+掺杂的硼硅酸盐玻璃在391 nm和462 nm激发下的下转换发光性能和能量传递特征。结果表明,用462 nm激发Eu3+掺杂的硼硅酸盐玻璃样品,发现随着Eu3+浓度的增加,Eu2O3含量为0.5%(摩尔分数)时达到发射强度最大值。对于Eu3+/Tb3+共掺的硼硅酸盐玻璃,在462 nm处呈现最强激发峰,其最强发射峰为612 nm的红光。而且随着Tb3+浓度的增加,Eu3+和Tb3+之间的能量传递加强,大大提高了612 nm红光的发射强度。     

载银硅酸盐玻璃缓蚀阻垢剂的研究进展

我国冷却水用量占工业用水总量的80%以上,如何实现冷却水节水与零排放对推进工业循环发展至关重要。缓蚀阻垢剂可有效解决冷却水系统的结垢腐蚀问题,提高冷却水的循环利用率。其中,载银硅酸盐玻璃缓蚀阻垢剂是一种缓释型不含磷的多功能水处理剂,同时具备抑菌、阻垢和缓蚀功能,且无二次污染问题,应用前景广阔。本研究重点详述了控释型载银硅酸盐玻璃缓蚀阻垢剂主成分功能及制备方法,总结分析了载银硅酸盐玻璃缓蚀阻垢剂研究现状、现存问题与发展趋势。     

玻璃封接电连接器的制备

采用硼硅酸盐玻璃作为封接玻璃材料,并与合金、碳钢等金属封接,制备了玻璃密封电连接器;制定了合理的玻璃粉体制备工艺及电连接器的封接制度.实验结果表明：制备的电连接器具有优良的电绝缘性能及很宽的使用温度范围.     

玻璃封接电连接器的制备

采用硼硅酸盐玻璃作为封接玻璃材料,并与合金、碳钢等金属封接,制备了玻璃密封电连接器;制定了合理的玻璃粉体制备工艺及电连接器的封接制度.实验结果表明:制备的电连接器具有优良的电绝缘性能及很宽的使用温度范围.     

高Eu3+浓度掺杂硼铋钙红光玻璃的制备与发光性能研究

采用传统熔融冷却法制备Eu3+掺杂的硼铋钙红光玻璃,研究不同Eu3+掺杂浓度下,玻璃的密度、摩尔体积、折射率等一般物理性质的变化规律;分析玻璃的激发、发射光谱及玻璃的结构和热稳定性,得到了一种高Eu3+掺杂浓度的红光玻璃.研究表明:随着Eu3+浓度的不断升高,玻璃的密度、折射率、玻璃转化温度和热稳定性逐渐升高,摩尔体积先减小后增大;8%(指摩尔分数,下同)为Eu₂O₃的较优掺杂浓度, 9%为玻璃成玻区中最大Eu₂O₃掺杂浓度.玻璃总体对称性均较低,为非晶态结构;玻璃结构致密程度先增大后减小,其结构单元主要包括[BO₃]三角体、[BO₄]四面体、[BiO₃]三角体和[BiO₆]八面体.制备的荧光玻璃因具有高的Eu3+掺杂浓度、与蓝光芯片的有效匹配度、优良的热稳定性、较低的熔点以及合适的折射率等特点,将有望成为白光LED用玻璃陶瓷的良好基质.      

Mn~(2+),Yb~(3+)共掺硼硅酸锌玻璃的长余辉性能与陷阱分布的研究

采用高温熔融法制备了Mn2+,Yb3+共掺的硼硅酸锌长余辉玻璃。通过荧光发射光谱、余辉发射光谱、余辉衰减曲线及热释光谱对材料的发光性能、结构、陷阱分布进行了表征,重点通过余辉衰减曲线和热释光谱分析了Yb3+掺杂浓度的变化对材料余辉性能和陷阱分布的影响,结果发现:ZBSMY玻璃的余辉发射源自于Mn2+的4T1(4G)→6A1g(6S)跃迁;共掺离子Yb3+按0.1%(摩尔分数)掺杂时,余辉性能最佳,陷阱的拟合深度分别0.79和1.04 eV,且浅陷阱浓度达到最大。     

锂硼合金的制备和性能研究

将纯度为99.9%(质量分数)的锂与纯度为90%～99%无定形硼粉按成分配比混合后, 放在特制的坩埚中在受控气氛(氦气和氢气的混合气)中熔炼, 制备出锂含量约70%的热电池阳极材料锂硼合金, 采用X射线衍射仪、扫描电镜、万能材料试验机、单元电池放电装置等设备对其物相结构、微观组织、力学性能及放电性能进行了检测和分析. X射线衍射和密度测试结果表明: 锂硼合金由自由金属锂和锂硼化合物两相组成, 制得的锂硼合金锭的均匀致密与否与熔炼温度有关. 与目前广泛使用的锂硅合金相比, 锂硼合金作为阳极材料所装配的单元电池在最高电压和放电工作时间这两方面具有更好的性能. 在不同的负载下, 锂硼合金阳极单元电池最高电压较锂硅合金阳极单元电池提高了0.10～0.27 V, 放电时间延长了11.4%～78.1%.     

Sm、Ce单掺以及Sm、Ce共掺CaO-B_2O_3-SiO_2玻璃中稀土离子的荧光性质研究

分别研究了单掺Sm2O3和CeO2以及共掺Sm2O3、CeO2的CaO-SiO2-B2O3玻璃的发光性质。单掺Sm2O3的CaO-SiO2-B2O3玻璃的光谱中出现典型的Sm3+的光谱性质;单掺CeO2的CaO-SiO2-B2O3玻璃的光谱中出现Ce3+的光谱性质,在332nm激发下,Ce3+发射蓝紫光,其发射光谱为一宽谱带,从350nm延展到500nm附近,主发射峰位于393nm,Stokes位移为61nm,只形成一个发光中心。当CaO-SiO2-B2O3玻璃共掺Sm2O3和CeO2时,出现Ce4+的发射峰,同时Sm3+的发光强度下降,说明作为一种新的激活剂Ce引入基质后,提高了Sm3+的局部对称性,Sm3+的f→f跃迁减弱,从而导致Sm3+的发光强度下降。在共掺Sm2O3、CeO2的CaO-SiO2-B2O3玻璃中Ce4+和Sm3+通过桥氧键相连。     

CaO-SiO2-B2O3:Eu3+玻璃的合成及发光性质研究

用常规的高温合成法合成了CaO-SiO2-B2OaEu2O3玻璃,探讨了玻璃的最佳合成温度、玻璃的网络结构并研究了其发光性质.在CaO-SiO2-B2O3;Eu2O3玻璃体系中观察到了Eu3+的发射光谱.样品的发射光谱有三个主要荧光发射峰,位于591nm左右的发射峰对应于Eu3+的5D0-7F1跃迁发射,位于618nm左右的发射峰对应Eu3+的5D0-7F2跃迁发射,位于650nm左右的发射峰对应于Eu3+的5D0-7F3.研究了掺杂Eu3+浓度对其发光强度的影响.并研究了Eu3+的发光强度与玻璃厚度的关系,玻璃的最佳厚度在2.0mm左右.光谱性质表明,这种玻璃体系能够把太阳光中的紫外光转换成红光,从而增强红光的发射强度.我们可以利用这些玻璃的发光性质来制备农用转光玻璃.     

Preparation and Optical Properties of Er^3＋-Doped Gadolinium Borosilicate Glasses

Er3 -doped Gd2 O3 -SiO2 -B2 O3 -Na2O glasses were prepared, and formation range of glass of Gd2 O3 -SiO2 -B2O3 system was experimentally obtained. It is found that the glass phase can be formed only when the content of SiO2 is 0～50%(molar fraction), Gd2O3 is 0～30%(molar fraction) and B2 O3 is above 20%(molar fraction) in this glass system. The glass can also be obtained but becomes translucent at the contents of 60%(molar fraction) SiO2 and 30% Gd2O3 , or at the contents of 60%(molar fraction) SiO2 and 30%(molar fraction) B2O3. There is no glass phase formed in other glass components. Glass forming ability for Gd2O3 content of 10%, was characterized by the value of β, the parameter of crystallization tendency, which is 0.32～1.76, obtained from the differential thermal analysis. The absorption and emission cross section, the J-O parameters Ωt(2,4,6) and radiative transition probabilities were calculated by using the theory of McCumber and Judd-Ofelt. The emission properties at 1.5 μm of the samples are discussed with the product of full width at half maximum and stimulated emission cross section. It can be seen that the value of the FWHM×σepeak product in the prepared glass is more than those of germanate, silicate and phosphate glasses. Furthermore, the maximum value of the product among these glasses reported in this work is close to that of oxyfluoride silicate glass. Therefore, the Er3 -doped gadolinium borosilicate glass in this paper is a candidate for broadband erbium doped fiber amplifiers.     

Spectroscopic Properties of Er^3＋-Doped TeO2-WO3-ZnO-ZnF2 Glasses

The Er^3 -doped TeO2-WO3-ZnO-ZnF2(TWZOF) glasses were prepared. The absorption spectra, 1.5μm emission spectra and fluorescence lifetimes of Er^3 , excited at 970nm, were measured. The J-O parameters Ωt(t=2, 4, 6), absorption and emission cross-sections were calculated. The dependence of the 1.5μm emission intensity, fluorescence lifetime and bandwidth of the Er^3 emission upon the contents of ZnF2 in glass were investigated. In TWZOF glass, Er^3 ions had a broad emission profile around 1.5μm with the maximum FWHM of 83nm. With the increasing of the content of ZnF2, the emission intensity at peak wavelength and the fluorescence lifetime of Er^3 at 1.5μm increase.     

Study on Thermal Stability and Spectroscopic Properties of Nd3+ -Doped Phosphate Laser Glasses

Fluorescence spectra, absorption spectra and thermal stability properties of Nd3 -doped phosphate laser glasses were tested in this work. We calculated spectroscopic parameters of Nd3 -doped phosphate laser glasses according to their absorption spectrum. Measuring and calculating linear thermal expansion coefficient, and analysising thermal stability of glasses show that this kind of Nd3 -doped phosphate laser glasses has thermal expansion coefficient α = 38.75× 10 -7/℃ and optimal spectroscopic properties which extend application range of Nd 3-doped phosphate laser glasses.     

Optical Spectroscopy of Er^3＋ and Er^3＋/Yb^3＋ Co-doped Bi2O3-GeO2-B2O3-ZnO Glasses

The （60 - x）Bi2O3 - xGeO2-30B2O3-10ZnO （x = 5, 10, 20, 30 molar percent） glasses doped with Er^3＋ and Er^3＋/Yb^3＋ were fabricated using the melting method. The thermal stability of the glasses was studied with their DTA curves. The results show that the difference between the glass transition temperature and the crystallization onset temperature increases with the increase of GeO2 content, indicating that the thermal stability of the glass has become better. The absorption spectra were recorded and the stimulated emission cross sections were calculated using the McCumber theory. The Ω2, O4, and Ω6 parameters,the transition probability, the radiative lifetime, and the fluorescence branch ratio of Er^3＋ for optical transition were calculated from their absorption spectra in terms of reduced matrix U^（t）（λ = 2, 4, 6） character for optical transitions. The infrared emission of Er^3＋ was measured upon excitation with 970 nm light and the full width at half-maximum （FWHM） was estimated from the emission spectra. The pumping efficiency and the intensity of the emission at the 1.54 μm band of Er^3＋ were enhanced considerably by co-doping Yb^3＋ .     

Spectroscopic Properties of Nd^3＋-Doped Tellurite Glasses

Spectroscopic Properties of Nd~(3 )-Doped Tellurite Glasses     

Spectroscopic Properties and Judd-Ofelt Theory Analysis of Er^3＋-Doped Heavy Metal Oxyfluoride Silicate Glass

Er^3 -doped heavy metal oxyfluoride silicate glass was fabricated and characterized, and the absorption spectrum and fluorescence spectrum of the glass were studied. The Judd-Ofelt intensity parameters Ωt(t=2, 4, 6), spontaneous transition probability, fluorescence branching ratio and radiative lifetime of each energy levels for Er^3 were calculated by Judd-Ofelt theory, and stimulated emission cross-section of ^4I13/2→^4I15/2 transition was calculated by McCumber theory. The results show that fluorescence full width at half maximum and stimulated emission cross-section of Er^3 -doped heavy metal oxyfluoride silicate glass are broad and large, respectively. Compared with other host glasses, the gain bandwidth property of Er^3 -doped heavy metal oxyfluoride silicate glass is close to those of tellurite and bismuth glasses, and has advantage over those of silicate, phosphate and germante glasses.     

Optical Limiting Respome in Er^3＋-Doped TeO2 -Nb2O5 -ZnO Glass

The nonlinear absorption properties of Er^3＋ doped telluride glass were investigated with picosecond laser pulses. The optical limiting response was measured with a transmission technique and reverse saturable absorption （RSA） with a Z-scan technique, which proved that the glass was a promising material for practical optical limiters. The experimental resulted showed that the excited absorption was responsible for the measured RSA, resulting in the optical limiting response. The measured data could be well simulated with a rate equation model to obtain the absorption cross sections of the excited state.     

Structure,Upconversion and Fluorescence Properties of Er3+-Doped TeO2-TiO2-La2O3 Tellurite Glass

Tellurite glasses were generally applied in rare earth optical materials due to their excellent physical and chemical properties. In this study, novel tellurite glasses composed of TeO₂-TiO₂-La₂O₃ were prepared by conventional melting-quenching method. Some basic physical parameters such as density, refractive indices, transition temperature and crystalline temperature were measured. The structure was analyzed by Raman spectra. The absorption, upconversion and fluorescence spectra were measured by UV-Vis-NIR spectrophotometer and spectrofluorimeter. Under 980 nm laser excitation, upconversion luminescence centered at 531, 545 and 657 nm corresponding to the transition ⁴H_11/2→⁴I_15/2, ⁴S_3/2→⁴I_15/2 and ⁴F_9/2→⁴I_15/2 respectively, were observed. The effects of TiO₂ concentration on structure and upconversion luminescence intensity were discussed. The result indicated that the upconversion intensity increased as the phonon concentration decreased. The fluorescence properties of Er³⁺ doped glass were also studied. The dominant peak centered at 1531 nm and full width at half maximum (FWHM) was 64 nm. The Er³⁺ stimulated emission cross-section was calculated on the basis of McCumber theory. The possible mechanism of upconvesion and fluorescence were proposed.     

Investigation on Preparation and Fluorescence Properties of Oxy-Fluoride Glass Co-Doped with Er^3＋ and Yb^3＋

The glass sample based on the composition of 45PbF2-45GeO2-10WO3 co-doped with Yb^3 /Er^3 was prepared by the fusion method in two steps : melted at 950℃ for 20～25min then annealed at 380℃ for 4 h. Through the V-prism it is found that the refractive index of host glass and the sample are 1.517 and 1.65 respectively. The transmittance was observed by using the ultraviolet-visible-infrared spectrometer in the wavelength range from 0.35 to 2.5μm. The transmittance of the host glass is beyond 73%. That of the sample is beyond 50% and there are characteristic absorption peaks of rare-earth ions. The emission spectrum was measured by using the Hitachi F-4500 fluorescent spectrometer pumped by 980nm semiconductor laser. There are a strong emission peak at 530 nm and a weak peak at 650 nm.