Q.S. Liu1
,
2
,
3)
,
L.C. Zhao3)
,
G.X. Dong2) and N.J. Gu1) 1) Heibei University of Technology
,
Tianjin 300130
,
China 2) Tianjin Institute of Technology
,
Tianjin 300191
,
China 3) Harbin University of Technology
,
Harbin 150001
,
China
金属学报(英文版)
Theconstruction changinginthereversetransformation ofthestress induced εMin Fe 17 Mn 10 Cr 5 Si 4 Ni alloy is carefully inspected in transmission electron microscope, and then stress induced εM procedure of reverse transformation is analyzed. The behavior of reverse transformationisdissimilar when the organization of εMis different. The reversetransfor mation ofεM withtheshapeofsingle plateandstripisrelativelyeasy,anditsreversibilityincrystallographiciseasilytocarryout,fortheεM with multilayerstructure,thereversetrans formationtakes placein isolatedlayers, fortheεMthat grows well,thereversetransforma tion isrelatively difficult becauseofthe ductile harmonization between itsinternalorganiza tion structures.
关键词:
stress induced εM
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null
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null
彭夷安
,
曹小妹
,
雷春华
,
刘利民
,
李其华
,
廉世勋
中国稀土学报
研究了Ba3La(BO3)3 基质中Dy3+ 的光致发光特性; 探讨了RE3+的电荷半径比(z/r)和Ce3+, Dy3+ 含量对Dy3+ 发光强度及发光颜色的影响; 分析了Ba3La(BO3)3 中Ce3+ 对Dy3+ 发光的敏化作用; 确定了Dy3+ 的 4F9/2→6H15/2及4F9/2→6H13/2跃迁发射的浓度猝灭机制均为电偶极-电四极相互作用.
关键词:
发光学
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Dy3+
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Ba3La(BO3)3
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光致发光
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浓度猝灭
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稀土
Journal of Luminescence
Ln(3+) (Ln = Nd, Sm, Eu, Gd, Dy, Ho, Er)-doped Y3GaO6 compounds were prepared by solid-state reaction, and their optical spectra such as absorption, photoluminescence, excitation and time-resolved spectra have been measured for Ln Nd, Sm, Dy, Ho, Er. X-ray powder diffraction shows that the lattice parameters of the compounds (Y(0.96)Ln(0.04))(3)GaO6 decrease with the decrease of the radii of trivalent Ln(3+) ions, indicating that Ln(3+) ions have substituted for y(3+) ions in the lattice. Optical spectra show that there are obvious absorptions at ultraviolet to visible region. The strong emissions in visible and infra-red region show that Y3GaO6 is a suitable host for rare-earth-doped laser crystal and phosphor materials. (C) 2004 Elsevier B.V. All rights reserved.
关键词:
crystal-field;absorption-spectra;luminescence;y3ga5o12;glasses;garnet;y2o3;ions;laf3;tb3
Journal of Alloys and Compounds
The subsolidus phase relations in the ZnO-MoO3-B2O3, ZnO-MoO3-WO3 and ZnO-WO3-B2O3 ternary systems have been investigated by the means of X-ray powder diffraction (XRD). There is no ternary compound in all the systems. There are five binary compounds and five tie lines in the ZnO-MoO3-B2O3 system. This system can be divided into six 3-phase regions. There are three binary compounds and three tie lines in the ZnO-MoO3-WO3 system. This system can be divided into four 3-phase regions. There are four binary compounds and four tie lines in the ZnO-WO3-B2O3 system. This system can be divided into five 3-phase regions. The possible component regions for ZnO single crystal flux growth were discussed. The phase diagram of Zn3B2O6-ZnWO4 pseudo-binary system has been constructed, and the result reveals this system is eutectic system. The eutectic temperature is 1007 degrees C and eutectic point component is 70 mol% Zn3B2O6. (c) 2007 Elsevier B.V. All rights reserved.
关键词:
ZnO-MoO3-B2O3;ZnO-MoO3-WO3;ZnO-WO3-B2O3;Zn3B2O6-ZnWO4;phase relation;zno single-crystals;zinc oxide;growth;moo3-wo3
XU Xiuguang WANG Changzhen TU Ganfeng Northeast University of Technology
,
Shenyang
,
China.
材料科学技术（英文）
Thermodynamic properties of 3Y_2O_3·5Al_2O_3 double compound have been determined with CaF_2 single crystal electrolyte galvanic cell at 1049 K to 1230 K.The galvanic cell used can be expressed as: Pt,O_2(g)丨Y_2O_3(s),YOF_((s))丨CaF_2丨YOF_((s)), 3Y_2O_3·5Al_2O_(3(s))丨Al_2O_(3(s))丨O_2(g),Pt, of which the cell reaction is; 3Y_2O_(3(s))+SAl_2O_(3(s))=3Y_2O_3·SAl_2O_(3(s)) The following result is obtained: A_fG°(3Y_2O_3·5Al_2O_3)=-939500+765.90T±710J/mol where,△fG°(3Y_2O_3·5Al_2O_3)is the free energy of formation of 3Y_2O_3·5Al_2O_3 from Y_2O_3 and Al_2O_3.
关键词:
rare earth
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null
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null
Journal of the American Ceramic Society
In situ synthesis of bulk Al(3)BC(3) was achieved via a reactive hot-pressing method using Al, B(4)C, and graphite powders at 1800 degrees C for 2 h. The reaction path for synthesizing Al(3)BC(3) was investigated. It was found that Al(3)BC(3) formed via the reaction of C, B(4)C, and Al(4)C(3) above 1180 degrees C. Dense Al(3)BC(3) was prepared with a little B(4)C and graphite remained. Microstructure observations revealed the plate-like morphology of Al(3)BC(3) grains. Moreover, the mechanical properties of Al(3)BC(3) were characterized (Vickers hardness of 11.1 GPa, bending strength of 185 MPa, fracture toughness of 2.3 MPa.m(1/2), and Young's modulus of 163 GPa). Young's modulus decreased slowly with increasing temperature, and at 1600 degrees C remained 79% of that at ambient temperature. These results show that Al(3)BC(3) is a promising lightweight high temperature structural material.
关键词:
boron-carbide;high-temperature;youngs modulus;aluminum;al8b4c7;friction;ti3alc2;ti3sic2;composites;ceramics
刘晓利
,
李月宝
,
杨书颖
,
崔玉杰
,
潘建国
,
王国富
人工晶体学报
采用提拉法(Czochralski)生长出了掺Yb3+的Sr3Gd(BO3)3晶体,晶体尺寸达到:25 mm×30 mm.测量了Yb3+: Sr3Gd(BO3)3晶体的吸收谱、荧光谱以及荧光寿命.Yb3+: Sr3Gd(BO3)3晶体在975 nm有一半峰宽为7 nm的强吸收峰,π谱的吸收跃迁截面σa=7.28×10-21 cm2,在1040 nm的发射跃迁截面σe=1.43×10-21 cm2.辐射寿命为1.46 ms, Yb3+浓度为13 at%时的荧光寿命f=2.14 ms,Yb3+浓度为0.5 at%时的荧光寿命f=1.21 ms.
关键词:
Sr3Gd(BO3)3晶体
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提拉法
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光谱参数
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激光晶体
郭锐
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万明
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张国春
,
周浪
人工晶体学报
本文采用固相反应法合成了一系列掺Nd3+的Na3La2(BO3)3(Na3La2(BO3)3:Nd3+)多晶粉末,X-ray粉末衍射分析表明,它们属于正交晶系,Amm2空间群.测试了Na3La2(BO3)3:Nd3+的红外光谱、反射光谱和荧光光谱,观察到试样在590 nm、740 nm和800 nm附近存在显著吸收,以及在878 nm、1067 nm、1326 nm三个发射带.研究了发光强度与Nd3+离子浓度之间的关系,确定了Nd3+离子在Na3La2(BO3)3基质中发光的适宜浓度为10 %摩尔分数.
关键词:
掺钕硼酸钠镧
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固相反应
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X-ray粉末衍射
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光谱特性
徐明祥
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焦正宽
无机材料学报
通过系统地测量（La2/3Ca1/3）（Mn（3-x）／3Fex／3）O3（x＝0、0.1、0．2、0．3的体系样品的电阻率-温度关系以及一定温度下磁电阻率与磁场的关系，发现随x的变化其磁电阻率峰和电阻率峰均发生位移，磁电阻率峰值增大，并伴生磁电阻率峰展宽效应．作者认为由于Fe的替代，引起体系中Mn3+／Mn4+比率及磁矩的变化，加之外场对磁有序结构的调制作用，从而影响了Mn3+－O－Mn4+的双交换作用，最终导致磁电阻行为发生变化．
关键词:
巨磁电阻效应
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null
