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Journal of Rare Earths 2005年第5期23卷 563-563页

作者： Wang Jinhao Zhang Jianli Zhang Yuepin Xia Haiping Laboratory of Photo-Electronic Matedals Ningbo University Ningbo 315211 China

The growth of LiNbO3 single crystal with Er^3＋/Zn^2＋ co-doped by the Bridgman method and the characteristics of absorption spectra and fluorescence spectra were reported. By means of the optimized con- ditions such as growth rate of 0.8 - 1.5 mm · h^- 1, temperature gradient about 30 - 35℃ ·cm^-1 across the solid-liquid interface and sealed platinum, large size crystals containing Zn^2＋（3%） and Er^3＋（0.6%） with good optical quality were obtained. X-ray diffraction and DTA were used to characterize the crystals. The results indicate that the concentration of Er^3＋ ions in crystals decrease along the growth direction, the absorption intensity and the fluorescence intensity ions also decrease along the growth direction. of Er^3＋ However, for the upper part crystal, the upconversion fluorescence intensity is higher than that of the lower part crystal excited with 800 or 970 nm pump. The effects of crystal lattice, structure defect and effective segregation of Er^3＋ ions were discussed in respect to the variations were discussed of upconversion fluorescence intensity.

关键词： LiNbO3 crystal Er^3 ＋/Zn^2 ＋ co-doping Bridgman method upconverison fluorescence rare earths

Photoluminescence properties of Tm^(3+)/Tb^(3+)/Sm^(3+) tri-doped Na_(5)Y_(9)F_(32) single crystal with high thermal stability for white light-emitting diodes

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Journal of Rare Earths 2021年第5期39卷 512-519页

作者： Yang Qiao Xiong Zhou Jianli Zhang Haiping Xia Hongwei Song Baojiu Chen Key Laboratory of Photo-electronic Materials Ningbo UniversityNingbo 315211China State Key Laboratory on Integrated Optoelectronics College of Electronic Science and Engineering and College of PhysicsJilin UniversityChangchun 130012China Department of Physics Dalian Maritime UniversityDalian 116026China

A novel Tm^(3+)/Tb^(3+)/Sm^(3+)tri-doped Na_(5)Y_(9)F_(32)single crystal was synthesized by a modified Bridgman method for the propose of white light emitting diodes.The fluorescence spectra of various Sm^(3+)ion concentrations and fixed 0.4 mol%Tm^(3+)and 0.5 mol%Tb^(3+)were measured and studied systematically excited by near-ultraviolet light of 355 nm.The Sm3+ion concentration takes apparent effect on the relative intensity of peaks in the visible region and the color coordinate combining from these emission bands.A near pure white light emission with color coordinates(0.3295,0.3057)and color temperature(5657 K)can be obtained when the concentrations of Tm^(3+),Tb^(3+)and Sm^(3+)ions are 0.4 mol%,0.5 mol%and 0.8 mol%,respectively.Furthermore,the practical down-conversion internal quantum yield was measured by integrating spheres at about 14.39%.The tri-doped Na_(5)Y_(9)F_(32)single crystal shows a high thermal stability inferring from the temperature dependent emission in which the integrated emission intensities are reduced only by^3%with the increase of temperature from 280 to 450 K.The present results demonstrate that the Tm^(3+)/Tb^(3+)/Sm^(3+)tri-doped Na_(5)Y_(9)F_(32)single crystal may provide a promising candidate for white light-emitting diodes,luminescent materials and fluorescent display devices.

关键词： Na_(5)Y_(9)F_(32)single crystal Tm^(3+)/Tb^(3+)/Sm^(3+) Bridgman method White light emission Rare earths

坩埚下降法生长BSO(Bi_4Si_3O_(12))闪烁晶体

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人工晶体学报 2000年第S1期29卷 10-页

作者： M.Ishii 1, K.Harada 1, Y.Hirose 1, N.Senguttuvan 1, M.Kobayashi 2, I.Yamaga 3, F.Shiji 4, F.Yiting 4 (1.SIT,Shonan Institute of Technology,Fujisawa,251 8511,Japan 2.KEK,High Energy Accelerator res.Organization,Tsukuba,30 0801,Japan 3.Futec

While the light output of BSO crystals is only 20% of the output of currently used BGO(Bi 4Ge 3O 12 )scintillation crystals,the decay time is one third(100ns).It is considered as promising for application as radiation detectors for high energy physics experiments.Based on this advantage,we have been proceeding with our development of large crystals to use practically.In this paper,we will review our results of crystal growth of BSO by Bridgman method and characterization on its scintillation performance. High purity raw materials of Bi 2O 3 and SiO 2 were mixed together,fired at 850℃,re mixed and sintered at 950℃.The charge was then fed into a Pt crucible of 25mm in diameter.For crystal growth,the crucible was lowered at 0.5mm/h in a furnace temperature gradient of about 10℃/cm.

关键词： BSO crystal Bridgman method radiation detector

Growth and spectroscopic characteristics of Nd-doped PbWO_4 crystal

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Chinese Physics B 2012年第5期21卷 323-329页

作者：王庆国苏良碧李红军熊巍袁晖郑丽和徐晓东吴锋唐慧丽姜大朋徐军 Key Laboratory of Transparent and Opto-Functional Inorganic Materials Shanghai Institute of CeramicsChinese Academy of Sciences Graduate University of the Chinese Academy of Sciences

Nd-doped PbWO4 crystals are grown by using the modified Bridgman method.The spectroscopic properties of the crystals are investigated.The changes of the absorption band at 350 nm are discussed for samples annealed at 740℃ and 1040℃.The radiative lifetime of the 4 F 3/2 level is calculated by using the Judd-Ofelt theory according to the absorption spectrum of 0.5 at.% Nd-doped PbWO 4 crystal.The spontaneous Raman scattering properties of the crystals are analysed.

关键词： PbWO 4 Bridgman method Judd-Ofelt theory Raman spectra

AN ALTERNATIVE APPROACH FOR CRYSTAL GROWTH AND PIEZOELECTRIC PROPERTIES OF 4-INCH DIAMETER LITHIUM TETRABORATE SINGLE CRYSTAL

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AN ALTERNATIVE APPROACH FOR CRYSTAL GROWTH AND PIEZOELECTRIC...

2016年全国压电和声波理论及器件应用研讨会

作者： Tian TIAN Wen-bin LIU Jia-yue XU Institute of Crystal Growth School of Materials Science and Engineering Shanghai Institute of Technology

Background, Motivation and Objective Lithium tetraborate(LiBO:LBO) single crystal has become a new type of temperature compensated surface acoustic wave(SAW) substrate material during the past two decades. Its mechanical and electrical coupling coefficient is 7 times higher than α-quartz and the temperature stability is better than lithium niobate. Otherwise, the cost of raw materials is only one-tenth of lithium tantalate single crystal, while with the same weight, the number of devices can be produced of LBO is more than 2 times than lithium tantalite single crystal. Thus, LBO single crystal is an excellent comprehensive surface acoustic wave substrate material, and it has a wide range of applications such as in high-frequency/ultra-high frequency SAW device design and production. Statement of Contribution/methods High purity(4N) LiCO and HBO powders were used as starting materials for LBO single crystal growth. The oxide mixtures were ground for 8h in mortar and sintered in air. LBO polycrystalline powders were obtained. And the feed materials were then loaded into the Pt crucible to grow single crystal in bridgman furnace as the seed crystal was chosen to be in our growth. Results 4-inch diameter LiBO slab crystal has been successfully grown by an alternative method. When the seed crystal was selected as , it was helpful to improve the growth speed as 5mm/d. Less twin crystal were found in the crystal. Discussion and Conclusions Lithium tetraborate single crystal is a superior substrate material for SAW and BAW devices. It was difficult for industrialization of 4-inch LBO crystal because tetraborate has large melt viscosity.

关键词： Lithium tetraborate single crystal Bridgman method Alternative method

来源： cnki会议评论

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热电材料的研究及进展

人工晶体学报 2000年第S1期29卷 7-页

作者：王继扬刘红魏景谦胡小波刘跃岗山东大学晶体材料国家重点实验室济南250100

In 1823,Thomas Seebeck first discovered the thermoelectric effect.A temperature difference across any electric conductor junction will generate a corresponding voltage difference.Probably the most familiar use of this so called Seebeck effect is thermocouple.When an electric current passing through junction which is composed of two dissimilar conductors results in the absorption or release of the heat,this is the Peltier effect.This effect makes thermoelectric refrigerator or heating devices possible.Moreover a power generator can be also invented from the application of thermoelectric materials.Thermoelectric materials are those which possess high thermoelectric figure of merit.The major problem for thermoelectric materials is poor efficiency.They are now used only in the fields in which cost is not a big problem such as space and some other instruments.Thermoelectric materials are not widely used nowadays.

关键词： thermoelectric materials Bridgman method La 0.9 Fe 3CoSb 12 nanometer materials

熔体生长中自然对流对溶质分凝和界面形状的影响

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人工晶体学报 2000年第S1期29卷 17-页

作者：刘永才陈万春中国科学院物理研究所天津大学化工学院天津300072

The uniformity of impurity distribution in a melt growth process is significantly determined by the melt convection and melt/crystal interface.Therefore,it is important to investigate the coupling effects of convection,segregation and growth interface shapes in order to largely improve the crystal quality. In this paper,we employ a finite element algorithm to study the vertical bridgman growth process of Te doped GaSb crystals.The calculation model consists of unsteady state equations of heat transfer,mass transfer and momentum transfer,as well as their correspondingly boundary and initial conditions.A boundary conformal mapping technique is used to obtain the free melt/crystal interface shape and position which is a prior unknown.The set of algebraic equations obtained after finite element discretion is iteratively solved by Newton Raphson method until a given criterion is reached.

关键词： Bridgman method natural convection segregation interface shape finite element method

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YCOB晶体的坩埚下降法生长条件研究

人工晶体学报 2000年第S1期29卷 83-页

作者：罗军钟真武范世 王锦昌中国科学院上海硅酸盐研究所上海200050

Ca 4YO(BO 3) 3(YCOB) which possesses good NLO properties and chemical stability,is an excellent candidate for frequency conversion crystals to produce green and blue light (SHG and THG of Nd∶YAG laser).In this paper,preparation of the feed material and the vertical bridgman growth condition for YCOB crystal is reported for the first time to our knowledge. YCOB crystals have been grown from the feed materials composed of Y 2O 3(4N),CaCO 3/CaO (A.R.) and H 3BO 3/B 2O 3(4N)by vertical Bridgman method.Since Ca 4YO(BO 3) 3 melts congruently,the feed material should be prepared in the stoichiometric composition.The evaporation of B 2O 3 at high temperature and the hygroscopicity of CaO,B 2O 3 and Y 2O 3 were carefully considered.It was showed by experiments that the feed material prepared by directly and thoroughly mixing together stoichiometric amount of Y 2O 3,CaO and B 2O 3 is suitable for the bridgman growth of YCOB crystal.The melting point of YCOB crystal is 1510℃,and Pt crucible less than 1.0mm thick was chosen.The temperature of the furnace was controlled from 1560℃ to 1650℃.Owing to the extremely high melting points of both Y 2O 3 and CaO,the feed material had been heated at the above temperature for more than 10 hours before growth so that it melts thoroughly.The growth rate of 0.2-0.6mm/h and the temperature gradient near the solid-liquid interface of 40-60°C/cm were chosen.The Crack free and transparent YCOB crystals with 25mm in diameter and 50mm long have been grown in near sealed Pt crucibles under the above growth condition,which suggests that the vertical Bridgman method is suitable for the growth of YCOB crystal.

关键词： Bridgman method Ca 4YO(BO 3) 3 nonlinear optical material

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弛豫铁电单晶PMNT的生长及压电性能

人工晶体学报 2000年第S1期29卷 87-页

作者： LUO Hao su, XU Gui sheng, XU Hai qing, QI Zhen yi, ZHONG Wei zhuo,YIN Zhi wen (Laboratory of Functional Inorganic Materials,Shanghai Institute of Ceramics, Chinese Academy of Sciences,Shanghai 201800,China) (E-mail:hluo@***)

It is difficult for the growth of relaxor ferroelectric single crystal (1 x ) Pb(Mg 1/3 Nb 2/3 )O 3 x PbTiO 3 (abbreviated as PMNT).The first reason is that there are four oxides as raw materials which are easily result in the nonstoichiometry and inhomogeneity for the single crystals,the second is that the pyrochlore phases appear easily for general growth condition that will reduce the dielectric and piezoelectric performance of PMNT single crystals,and the third is that the platinum crucible is easily leaked at the melting temperature of PMNT.A feasible technique has been used for the growth of PMNT single crystals after we researched the stability,structure and relation of PMN PT phases at high temperature.Now we can fabricate the large size and high quality of PMNT single crystals by a modified bridgman technique.

关键词： ferroelectric single crystal PMNT Bridgman method piezoelectric properties