Novel low-temperature synthesis of glasses and glass-ceramics in the B2O3-SiO2-P2O5 system

In recent years considerable progress has been made in electronic packaging substrate technology. The future need of miniaturization of devices to increase the signal processing speed calls for an increase in the device density requiring the substrates to be designed for better thermal, mechanical and electrical efficiency. Fast signal propagation with minimum delay requires the substrate to possess very low dielectric constant. Several glasses and glassceramic materials have been identified over the years which show good promise as candidate substrate materials. Among these, borophosphate and borophosphosilicate glass-ceramics have been recently identified to have the lowest dielectric constant (3.8). Sol-gel processing has been used to synthesize borosilicate, borophosphosilicate and borophosphate glasses and glass-ceramics using inexpensive boron oxide and phosphorus pentoxide precursors. Preliminary results of the processing of these gels and the effect of volatility of boron alkoxide and its modification on the gel structure are described. X-ray diffraction, differential thermal analysis and Fourier transform-infrared spectroscopy have been used to characterize the as-as-prepared and heat-treated gels.     

Optical absorption studies for TeO2-P2O5 and Bi2O3-TeO2-P2O5 glasses

A range of TeO₂-P₂O₅ and Bi₂O₃-TeO₂-P₂O₅ glass systems were prepared. The optical absorption spectra were measured in the spectral range 300–800 nm and it was found that the fundamental absorption of these glasses is dependent on the glass composition. The optical energy gap of binary glasses increases with increasing TeO₂ content while the addition of Bi₂O₃ to TeO₂-P₂O₅ decreases the optical energy gap. The absorption edges of these glasses arise from direct forbidden transitions and occur at photon energies in the range of 2.17 to 2.97 eV for TeO₂-P₂O₅ glasses and 2.63 to 2.32 eV for Bi₂O₃-TeO₂-P₂O₅ glasses depending on their composition.     

Sol-Gel法制备B2O3-P2O5-SiO2系低介玻璃陶瓷

采用溶胶－凝胶法,以正硅酸乙酯和硼酸、磷酸为原料,制备出一种ＢＰＳ超细粉．使用这种超细粉,可在低于９５０℃空气气氛中烧结,获得性能优良的低分电常数、低损耗玻璃陶瓷．该种材料的介电常数ε≤５、介电损耗ｔａｎδ＜３×１０^－３（１ＭＨｚ）,有望用于超高频叠层片式电感领域．     

Preparation of B2O3-P2O5-SiO2 coating films by the sol-gel method

ThexB₂O₃ · (20-x) P₂O₅ · 80SiO₂ (in mol%) glass films withx=0, 10 and 20 have been prepared from metal alkoxides by carrying out the coating in a dry atmosphere. These coating films have shown a larger value of load at scratch and a smaller shrinkage during heat-treatment by replacing P₂O₅ in the films with B₂O₃. It has been found that B₂O₃ more effectively reduces the glass transition temperature of SiO₂ glass than P₂O₅. The concentrations of sodium ions, which migrated from soda-lime-silica glass substrates during the film formation, were higher in phosphosilicate and borophosphosilicate films than in borosilicate and pure silica films. This finding should be ascribed to the gettering effects of phosphorus for sodium ions.     

Fe2O3掺杂对ZnO-B2O3-P2O5-RnOm玻璃热学性能的影响

在ZnO-B<,2>O<,3>-P<,2>O<,5>-R<,n>O<,m>玻璃中掺杂0～5%(摩尔含量)的Fe<,2>O<,3>,分析了Fe<,2>O<,3>对热膨胀系数(α)、密度(ρ)、电阻率(RV)的影响,通过差热分析(DTA)、红外光谱和X射线衍射(XRD)分析了玻璃的结构.研究表明:Fe<,2>O<,3>的摩...     

氧化锆/锌硼硅微晶玻璃的制备与研究

在锌硼硅玻璃中添加0％～20％（wt）的超细部分稳定氧化锆粉体，分别采用熔融法和烧结法制备氧化锆／锌硼硅微晶玻璃。通过对实验现象的观测与分析，发现采用烧结法可以较好地制备氧化锆／锌硼硅微晶玻璃。采用X射线衍射仪观测玻璃样品中的晶相组成，用烧结点试验仪测试微晶玻璃的半球温度，通过维氏硬度计在玻璃表面的压痕尺寸计算微晶玻璃的韧性。结果表明，在ZnO-B2O3-SiO2玻璃中添加部分稳定超细ZrO2后，微晶玻璃的烧结温度升高，韧性得到很大的改善。     

添加Bi2O3对ZnO-B2O3-P2O5-SrO体系封接玻璃结构和性能的影响

采用熔融法制备了ZnO-B2O3-P2O5-SrO-Bi2O3系无铅磷酸盐封接玻璃,研究了Bi2O3对该体系玻璃的结构、特征温度、热膨胀系数和化学稳定性的影响。结果表明,随Bi2O3含量的增加,玻璃的密度增大,Tg、Tf先下降后趋于平缓,玻璃的热膨胀系数先上升后趋于平缓;化学稳定性先增强后降低,当Bi2O3为7mol时,达到极小值。     

Compositional dependence of infrared absorption spectra studies for TeO2-P2O5 and TeO2-P2O5-Bi2O3 glasses

The infrared absorption spectra of the vitreous TeO₂-P₂O₅ and Bi₂O₃-TeO₂-P₂O₅ systems are studied in the spectral region of 4000 to 200 cm^–1. Absorption bands in this range are assigned. The midband wavenumber and the absorption intensity for the attributed bands are found to be strongly and systematically dependent on glass composition. Quantitative analysis was also attempted to justify our attribution of the observed bands.     

Study of structures and properties of ZnO-Sb2O3-P2O5-Na2O glasses

The influence of ZnO substitution by 0–12 wt.% Na₂O on the properties of ZnO-Sb₂O₃-P₂O₅-Na₂O glasses has been investigated. The structure and properties of the glasses with the composition of (13.86-x)ZnO-57.93Sb₂O₃-28.21P₂O_5?x Na₂O (x = 0–12 wt.%) were characterized by infrared spectra (IR), X-ray diffraction and differential thermal analysis (DTA). The results of IR indicated an increase in the intensity of symmetric vibrations of P-O-P bond, which was confirmed by the improvement of water durability with the increasing amount of Na₂O in the range of 0–10 wt.%. Substitution of 10 wt.% Na₂O led to the weight loss of the glass to 5.93 mg/cm^?2 after immersion in deionized water at 50 °C for 24 h. The results of XRD showed that the ability of crystallization decreased, indicating the good thermal stability of the glass. The glass containing 8 wt.% Na₂O had the best properties in every respect and might be an alternative to lead based glasses for the applications, providing further composition improvement.     

Sm3+:ZnO-B2O3-Al2O3-SiO2系透明玻璃陶瓷的制备和表征

采用熔融和晶化技术合成出含ZnAl2O4微晶的Sm3+:ZnO-B2O3-Al2O3-SiO2(ZBAS)玻璃陶瓷材料,并通过DSC、XRD、SEM和UV-Vis-Nir分光光度计和傅里叶变换荧光光谱仪等对样品进行了表征.结果表明,玻璃陶瓷主晶相为ZnAl2O4,晶相粒径为30nm;可见光透过率为最高可达70％,近红外透过率为70％～85％.该玻璃陶瓷能够受激发射出红光,且发光强度高于同组分的玻璃.