Among new low-melting-point glasses, bismuth ate glass is deemed to have the most potential as an environmentally friendly replacement for polluting Pb-containing glasses. Current studies of boro-bismuthate glasses fo...Among new low-melting-point glasses, bismuth ate glass is deemed to have the most potential as an environmentally friendly replacement for polluting Pb-containing glasses. Current studies of boro-bismuthate glasses focus on the structural influence of the additional oxide in the context of low-melting-point electronic sealing applications. In this study, the structure of quaternary Bi2O3- ZnO-B2O3-BaO glasses was investigated spectroscopic ally, with Fourier-transform-infrared (FT-IR) and Raman spectra recorded for glasses with different main oxide contents. Signals in the FT-IR are mainly observed around 500 cm﹣1, 720 cm﹣1, 840 cm﹣1, 980 - 1080 cm﹣1, and 1200 - 1500 cm﹣1, while the Raman scattering peaks are located at 130 cm﹣1, 390 cm﹣1, 575 cm﹣1, 920 cm﹣1, and 1250 cm﹣1. The glasses are mainly structured around [BO3] units and the numbers of [BiO6] and [BiO3] units increase with the Bi2O3 content increasing. Concurrently, the FT-IR absorption peaks associated with [BO4] units shift to lower wave numbers, indicating a loosening of the glass structure. However, as the B2O3 content is increased, the numbers of [BO3] and [BO4] units increase, while those of [BiO3] and [BiO6] units decrease, highlighting a densification of the glass structure. ZnO acts as a network modifier in these glasses.展开更多
Iron ions were used as probes to explore the structural and magnetic properties of 70TeO2'25B2O3' 5SrF2 vitreous matrix. The distribution of Fe3+ ions on different structural aggregates was revealed by means ...Iron ions were used as probes to explore the structural and magnetic properties of 70TeO2'25B2O3' 5SrF2 vitreous matrix. The distribution of Fe3+ ions on different structural aggregates was revealed by means of EPR, as depending on Fe2O3 concentration. Strongly distorted octahedral sites were detected for the isolated paramagnetic ions, and also clusters of Fe ions especially at high Fe2O3 content of samples. Magnetic susceptibility measurements evidenced both dipoledipole and superexchange type interactions involving iron ions. Mixed valence states of iron ions were also detected展开更多
The 40Bi2O3-30B2O3-(30-x)ZnO-xSrO (x=0-15mol%,BBZSr) glass system was prepared by the conventional melt quenching method.The effect of SrO addition on structure,thermal properties,chemical stability and sealing perfor...The 40Bi2O3-30B2O3-(30-x)ZnO-xSrO (x=0-15mol%,BBZSr) glass system was prepared by the conventional melt quenching method.The effect of SrO addition on structure,thermal properties,chemical stability and sealing performance of BBZSr glass were investigated thoroughly.The experimental results show that the total proportions of [BO3] group and [BO4] group decrease and the vibrations of [BiO3] group and [BiO6] group become weaker with the increase of SrO addition content,suggesting the glass network structure is strengthened owing to the SrO addition.Hence,both the thermal and chemical stability were significantly improved as the SrO content was increased.When the SrO content increased from 0 to 15mol%,the glass transition temperature and softening temperature slightly increased from 380 to 388 ℃ and from 392.7 to 402.2 ℃,respectively,meanwhile the coefficient of thermal expansion also increased from 10.49×10^-6 to 11.16×10^-6/℃ (30-300 ℃).The BBZSr glass with 15mol% SrO exhibited excellent comprehensive properties with low glass transition temperature(384.9 ℃),low softening temperature(400.3 ℃),high coefficient of thermal expansion (11.14×10^-6 ℃,30-300 ℃),good thermal and chemical stability.Besides,the glass had the good wetting behavior and sealing performance for Al-50%Si alloy.展开更多
A series of novel Er^3＋/Yb^3＋ co-doped （85- x ） TeO2-15WO3-xB2O3 （TWB;x=2%,5%,8%（mole fraction） ） glasses were prepared. Influence of B203 on the spectroscopic properties of Er^3＋/Yb^3＋ co-doped tungsten-tel...A series of novel Er^3＋/Yb^3＋ co-doped （85- x ） TeO2-15WO3-xB2O3 （TWB;x=2%,5%,8%（mole fraction） ） glasses were prepared. Influence of B203 on the spectroscopic properties of Er^3＋/Yb^3＋ co-doped tungsten-tellurite glasses were investigated. It is found that the intensity of 1.5μm fluorescence, lifetime of the ^4I13/2 level and upconversion fluorescence all decrease with the increase of B2O3 content. The product of full width at half maximum （FWHM） and stimulated emission cross-section （σe^peak） of Er^3＋ ：^4I13/2→^4I15/2 transition has an optimum when B203 is 5% （mole fraction）. The emission spectra of Er^3＋ ： ^4I13/2→^4I15/2 transition was analyzed using peak-fit routine, and an equivalent four-level system was proposed to estimate the stark splitting for the 411512 and ^4I13/2 levels of Er^3＋ ions in TWB glasses at room temperature.展开更多
Erbium-doped glass showing the wider 1.5-um emission band is reported in a novel oxide system TeO2-WO3-Nb2O5 and their thermal stability and optical properties such as absorption, emission spectra, cross-sections and ...Erbium-doped glass showing the wider 1.5-um emission band is reported in a novel oxide system TeO2-WO3-Nb2O5 and their thermal stability and optical properties such as absorption, emission spectra, cross-sections and fluorescence lifetime were investigated. Compared with other glass hosts, the gain bandwidth properties of Er3+ in TWN glass is close to that of bismuth glasses, and larger than those of tellurite, germanate, silicate and phosphate glasses. The broad and flat 4I13/2-4I15/2 emission and the large stimulated emission cross-section of Er3+ ions around 1.5um can be used as host material for potential broadband optical amplifier in the wavelength-division-multiplexing (WDM) network system.展开更多
BaO-La2O3-B2O3 （BLB） glass, suitable to be used as a sealing between metals, was chosen to be the binder in preparing glass coats on the Ti-alloy substrate. The SiCN nano-powder was introduced as the filler for the ...BaO-La2O3-B2O3 （BLB） glass, suitable to be used as a sealing between metals, was chosen to be the binder in preparing glass coats on the Ti-alloy substrate. The SiCN nano-powder was introduced as the filler for the absorbing coat because it is considered to be a good high temperature absorber. The effect of the coating temperature and coating time on the tensile strength of the glass coat was investigated and the proper coating parameters to get good mechanical properties were determined. In addition, the effects of the SiCN content on the tensile strength of the absorbing coat were also discussed. Results show that it is possible to prepare the glass coat using the BLB glass as a binder. That the coat formed at 730℃ for 30 min has the best tensile strength witnesses 730 ℃, 30 min to be the proper parameter to prepare the glass coat. The BLB glass coat without SiCN powder possesses good tensile strength and the introduction of the SiCN absorber into the glass coat will lower the tensile strength. As the SiCN content increases, the tensile strength of the absorbing coat decreases, which could be attributed to the aggregation of SiCN in the coats.展开更多
We have performed time-resolved degenerate four-wave mixing (DFWM) experiments in 75Nb2O5-20TeO2-5ZnO glasses doped by Er2O3 at different excitation intensities and lattice temperatures. DFWM signal exhibits three pea...We have performed time-resolved degenerate four-wave mixing (DFWM) experiments in 75Nb2O5-20TeO2-5ZnO glasses doped by Er2O3 at different excitation intensities and lattice temperatures. DFWM signal exhibits three peaks at high excitation intensities, where a main peak appears at zero time delay and two rather weak side peaks locate symmetrically at the negative and positive time delay, respectively. The main peak is attributed to local-field effect and two side peaks are attributed to Coulomb interaction (CI).展开更多
Owing to adjustable thermal expansion performance, BaO–CaO–Al_2O_3–B_2O_3–SiO_2(BCABS) glass has a promising commercialization prospect for intermediate temperature-solid oxide fuel cells(IT-SOFCs) sealing. Herein...Owing to adjustable thermal expansion performance, BaO–CaO–Al_2O_3–B_2O_3–SiO_2(BCABS) glass has a promising commercialization prospect for intermediate temperature-solid oxide fuel cells(IT-SOFCs) sealing. Herein, Al_2O_3 with two different contents was added into the same glass formulation, referred to as A and B glass, respectively. In terms of the non-isothermal crystallization kinetic behavior, the effect of Al_2O_3 as the unique intermediate was innovatively studied on the long-term performance of BCABS sealing glass. After the heat treatment at 1023 K for 100 h, the change of the network structure and the expansion coefficient of the glass were characterized. The results showed that the addition of Al_2O_3 as a network forming body could enhance the structure of glass, and increase the activation energy for glass transition, which could effectively inhibit the crystallization ability of sealing glass. Therefore, the B glass with the higher Al_2O_3 content showed the better long-term sealing ability, which was greatly beneficial for IT-SOFCs sealing.展开更多
An adhesive of the SiBCN ceramic was synthesized through the polymer derived ceramics(PDC)route.Meanwhile with higher adhesion strength and simpler process condition,the polyborosilazane(PSNB)was modified by E-44 epox...An adhesive of the SiBCN ceramic was synthesized through the polymer derived ceramics(PDC)route.Meanwhile with higher adhesion strength and simpler process condition,the polyborosilazane(PSNB)was modified by E-44 epoxy resin.The E-44 epoxy resin was used to promote the oxidation process of SiBCN,in other words,to produce more amount of SiO2-B2O3 glasses.The phase composition,elemental analysis,chemical bonds and microstructure were investigated by using X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),and scanning electron microscope(SEM)measurements.The E-44 modified adhesives were cured at 120℃in air for 2 h,and were pyrolyzed at 1200,1400,and 1500℃for 2 h in air,respectively.The highest adhesion strength of the modified adhesive was up to 5.33,12.23,and 12.50 MPa after being heat treated at 1200,1400,and 1500℃,respectively.Finally,we proposed an adhesion model and revealed the adhesion mechanism of SiBCN ceramic.展开更多
文摘Among new low-melting-point glasses, bismuth ate glass is deemed to have the most potential as an environmentally friendly replacement for polluting Pb-containing glasses. Current studies of boro-bismuthate glasses focus on the structural influence of the additional oxide in the context of low-melting-point electronic sealing applications. In this study, the structure of quaternary Bi2O3- ZnO-B2O3-BaO glasses was investigated spectroscopic ally, with Fourier-transform-infrared (FT-IR) and Raman spectra recorded for glasses with different main oxide contents. Signals in the FT-IR are mainly observed around 500 cm﹣1, 720 cm﹣1, 840 cm﹣1, 980 - 1080 cm﹣1, and 1200 - 1500 cm﹣1, while the Raman scattering peaks are located at 130 cm﹣1, 390 cm﹣1, 575 cm﹣1, 920 cm﹣1, and 1250 cm﹣1. The glasses are mainly structured around [BO3] units and the numbers of [BiO6] and [BiO3] units increase with the Bi2O3 content increasing. Concurrently, the FT-IR absorption peaks associated with [BO4] units shift to lower wave numbers, indicating a loosening of the glass structure. However, as the B2O3 content is increased, the numbers of [BO3] and [BO4] units increase, while those of [BiO3] and [BiO6] units decrease, highlighting a densification of the glass structure. ZnO acts as a network modifier in these glasses.
文摘Iron ions were used as probes to explore the structural and magnetic properties of 70TeO2'25B2O3' 5SrF2 vitreous matrix. The distribution of Fe3+ ions on different structural aggregates was revealed by means of EPR, as depending on Fe2O3 concentration. Strongly distorted octahedral sites were detected for the isolated paramagnetic ions, and also clusters of Fe ions especially at high Fe2O3 content of samples. Magnetic susceptibility measurements evidenced both dipoledipole and superexchange type interactions involving iron ions. Mixed valence states of iron ions were also detected
基金the Open Project Program of Key Laboratory of Inorganic Functional Materials and Devices,Chinese Academy of Sciences(No.KLIFMD-2018-06)。
文摘The 40Bi2O3-30B2O3-(30-x)ZnO-xSrO (x=0-15mol%,BBZSr) glass system was prepared by the conventional melt quenching method.The effect of SrO addition on structure,thermal properties,chemical stability and sealing performance of BBZSr glass were investigated thoroughly.The experimental results show that the total proportions of [BO3] group and [BO4] group decrease and the vibrations of [BiO3] group and [BiO6] group become weaker with the increase of SrO addition content,suggesting the glass network structure is strengthened owing to the SrO addition.Hence,both the thermal and chemical stability were significantly improved as the SrO content was increased.When the SrO content increased from 0 to 15mol%,the glass transition temperature and softening temperature slightly increased from 380 to 388 ℃ and from 392.7 to 402.2 ℃,respectively,meanwhile the coefficient of thermal expansion also increased from 10.49×10^-6 to 11.16×10^-6/℃ (30-300 ℃).The BBZSr glass with 15mol% SrO exhibited excellent comprehensive properties with low glass transition temperature(384.9 ℃),low softening temperature(400.3 ℃),high coefficient of thermal expansion (11.14×10^-6 ℃,30-300 ℃),good thermal and chemical stability.Besides,the glass had the good wetting behavior and sealing performance for Al-50%Si alloy.
基金Project supported bythe National Natural Science Foundation of Zhejiang Province (104498) ,the Foundation of Science andTechnology Bureau of Zhejiang Province (2005C31014 and 2006C21082)
文摘A series of novel Er^3＋/Yb^3＋ co-doped （85- x ） TeO2-15WO3-xB2O3 （TWB;x=2%,5%,8%（mole fraction） ） glasses were prepared. Influence of B203 on the spectroscopic properties of Er^3＋/Yb^3＋ co-doped tungsten-tellurite glasses were investigated. It is found that the intensity of 1.5μm fluorescence, lifetime of the ^4I13/2 level and upconversion fluorescence all decrease with the increase of B2O3 content. The product of full width at half maximum （FWHM） and stimulated emission cross-section （σe^peak） of Er^3＋ ：^4I13/2→^4I15/2 transition has an optimum when B203 is 5% （mole fraction）. The emission spectra of Er^3＋ ： ^4I13/2→^4I15/2 transition was analyzed using peak-fit routine, and an equivalent four-level system was proposed to estimate the stark splitting for the 411512 and ^4I13/2 levels of Er^3＋ ions in TWB glasses at room temperature.
基金This work was supported by the Project oftheNational NNatural Science Foundation of China(No.60207006) and Optical Science and Technology of Shanghai(No022261046).
文摘Erbium-doped glass showing the wider 1.5-um emission band is reported in a novel oxide system TeO2-WO3-Nb2O5 and their thermal stability and optical properties such as absorption, emission spectra, cross-sections and fluorescence lifetime were investigated. Compared with other glass hosts, the gain bandwidth properties of Er3+ in TWN glass is close to that of bismuth glasses, and larger than those of tellurite, germanate, silicate and phosphate glasses. The broad and flat 4I13/2-4I15/2 emission and the large stimulated emission cross-section of Er3+ ions around 1.5um can be used as host material for potential broadband optical amplifier in the wavelength-division-multiplexing (WDM) network system.
文摘BaO-La2O3-B2O3 （BLB） glass, suitable to be used as a sealing between metals, was chosen to be the binder in preparing glass coats on the Ti-alloy substrate. The SiCN nano-powder was introduced as the filler for the absorbing coat because it is considered to be a good high temperature absorber. The effect of the coating temperature and coating time on the tensile strength of the glass coat was investigated and the proper coating parameters to get good mechanical properties were determined. In addition, the effects of the SiCN content on the tensile strength of the absorbing coat were also discussed. Results show that it is possible to prepare the glass coat using the BLB glass as a binder. That the coat formed at 730℃ for 30 min has the best tensile strength witnesses 730 ℃, 30 min to be the proper parameter to prepare the glass coat. The BLB glass coat without SiCN powder possesses good tensile strength and the introduction of the SiCN absorber into the glass coat will lower the tensile strength. As the SiCN content increases, the tensile strength of the absorbing coat decreases, which could be attributed to the aggregation of SiCN in the coats.
基金This work was suPPorted by Shanghai Priority Academic DisciPline,the National Natural Science Foundation of China(No.10234030 and 10074015),the National Key Project for Basic Research(No.1999075204),the Project Sponsored by Shangliai Science and Tech
文摘We have performed time-resolved degenerate four-wave mixing (DFWM) experiments in 75Nb2O5-20TeO2-5ZnO glasses doped by Er2O3 at different excitation intensities and lattice temperatures. DFWM signal exhibits three peaks at high excitation intensities, where a main peak appears at zero time delay and two rather weak side peaks locate symmetrically at the negative and positive time delay, respectively. The main peak is attributed to local-field effect and two side peaks are attributed to Coulomb interaction (CI).
基金financially supported by the research project of National Natural Science Foundation of China (Grant Nos.51662015 and 51462011)
文摘Owing to adjustable thermal expansion performance, BaO–CaO–Al_2O_3–B_2O_3–SiO_2(BCABS) glass has a promising commercialization prospect for intermediate temperature-solid oxide fuel cells(IT-SOFCs) sealing. Herein, Al_2O_3 with two different contents was added into the same glass formulation, referred to as A and B glass, respectively. In terms of the non-isothermal crystallization kinetic behavior, the effect of Al_2O_3 as the unique intermediate was innovatively studied on the long-term performance of BCABS sealing glass. After the heat treatment at 1023 K for 100 h, the change of the network structure and the expansion coefficient of the glass were characterized. The results showed that the addition of Al_2O_3 as a network forming body could enhance the structure of glass, and increase the activation energy for glass transition, which could effectively inhibit the crystallization ability of sealing glass. Therefore, the B glass with the higher Al_2O_3 content showed the better long-term sealing ability, which was greatly beneficial for IT-SOFCs sealing.
基金Funded by the Research Fund of the National Key Research and Development Program of China(No.2017YFB0703200)the State Key Laboratory of Solidification Processing(NWPU),China(No.135-QP-2015)the Fundamental Research Funds for the Central Universities(No.3102017zy058).
文摘An adhesive of the SiBCN ceramic was synthesized through the polymer derived ceramics(PDC)route.Meanwhile with higher adhesion strength and simpler process condition,the polyborosilazane(PSNB)was modified by E-44 epoxy resin.The E-44 epoxy resin was used to promote the oxidation process of SiBCN,in other words,to produce more amount of SiO2-B2O3 glasses.The phase composition,elemental analysis,chemical bonds and microstructure were investigated by using X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),and scanning electron microscope(SEM)measurements.The E-44 modified adhesives were cured at 120℃in air for 2 h,and were pyrolyzed at 1200,1400,and 1500℃for 2 h in air,respectively.The highest adhesion strength of the modified adhesive was up to 5.33,12.23,and 12.50 MPa after being heat treated at 1200,1400,and 1500℃,respectively.Finally,we proposed an adhesion model and revealed the adhesion mechanism of SiBCN ceramic.
