四硼酸钾（K2B4O7.4H2O）晶体的生长和性能

本文报道了四硼酸钾晶体的生长,采用缓慢降温法自水溶液中首次生长出透明的大单晶体,尺寸为35×55×30mm。晶体的粉末倍频强度大于KB_5晶体。测量了晶体的透光光谱,压电和介电常数。     

温梯法生长φ110 mm×80 mm蓝宝石晶体位错的化学腐蚀形貌分析

利用导向籽晶温度梯度法（ＴＧＴ）生长了φ１１０ｍｍ×８０ｍｍ的蓝宝石单晶,应用化学腐蚀、光学方法分析了该晶体不同部位、不同切片的位错腐蚀形貌、位错密度及其分布情况、发现在晶体放肩处的（１１２０）面位错密度约为１０＾４ｃｍ＾－２量级,等径生长过程中造晶体中心处（０００１）面位错密度为（３￣４）×１０＾３ｃｍ＾－２,靠近坩埚壁处（０００１）面晶体位错密度为（５￣６）×１０＾４ｃｍ＾－２,用同样方法分析     

第三代手机陶瓷压电变换器

京都技术研究所开发了效率高达 90 %的陶瓷压电变换器电路 ,可用于第三代手机的背景光驱动等方面。此次开发的陶瓷压电变换器电路 ,外形尺寸为 48ｍｍ× 8ｍｍ× 1 .5ｍｍ ,重量为 1 78ｇ。该电路的特点是小巧。与现有的陶瓷压电变换器电路相比 ,体积缩小到了近 1 /1 5左右。其中巧妙地设计了单层分析翻转型陶瓷压电变压器的电极结构 ,并使升压电路单一化 ,从而达到了小型化和低消耗电力化。驱动冷阴极管时的消耗电力为 0 5Ｗ左右。以往 ,手机的背景灯使用较多的ＬＥＤ(ＬｉｇｈｔＥｍｉｔｔｉｎｇＤｉｏｄｅ)或无机ＥＬ(Ｅｌｅｃｔｒｏｌ…     

双掺锌钕铌酸锂激光晶体光学特性的研究

采用提拉法在优化条件下生长锌钕双掺的铌酸锂晶体。Nd2O3和ZnO的掺入量分别为0.2％和6％(in mole)。提拉速度为1 mm/h,旋转速度为20 r/min,生长的晶体尺寸为φ30 mm×40 mm。晶体的红外光谱测试表明,Zn:Nd:LiNbO3晶体的H-O振动吸收蜂发生了劈裂,在3 483 cm-1和3 530 cm-1形成吸收,而Nd:LiNbO3晶体的H-O振动吸收峰在3 483 cm-1处形成吸收。通过光斑畸变法测得Zn:Nd:LiNbO3晶体的光折变阈值强度为1.82×104W/cm2,比Nd:LiNbO3晶体的1.62×103W/cm2高1个数量级;采用逐点扫描的方式测得Zn:Nd:LiNbO3晶体双折射梯度为3×10-5cm-1。,比Nd:LiNbO3晶体的双折射梯度6×10-4cm-1小1个数量级。用合适的泵浦光测试了晶体自倍频性质,在150℃时当泵浦脉冲光能为40 mJ时,晶体的自倍频输出光能为35μJ。     

压电陶瓷驱动器材料

介绍一种压电应变常数ｄ３１大于３００×１０＾－１２ｍ／ｖ，居里温度大于１５０℃，介电常数小于５０００的压电陶瓷驱动器材料。     

极性微晶玻璃的恒温定向析晶

采用恒温析晶工艺制备了晶粒定向的ＳｒＯ－ＴｉＯ２－ＳｉＯ２极性微晶玻璃，其压电常数ｄ３３＝１２×１０＾－１２Ｃ／Ｎ，可用于制作水听器等压电传感器件，用ＳＥＭ研究了晶体生长形貌，讨论了该玻璃的定向析晶特性，证明了Ｓｒ２ＴｉＳｉ２Ｏ８晶体具有自发形成晶体极轴地玻璃表面向玻璃内部定向生长的特性，使之在恒温场中即可定向析晶。     

激光新材料Nd^3^＋：Li6Y（BO3）3晶体的助熔剂生长

合成出不同Ｎｄ＾３＾＋掺杂浓度的ＬＹＢ系列粉末样品，进行了荧光测试。用差热分析法测定了熔体的生长温度曲线。用助熔剂法生长出尺寸为６５ｍｍ×３０ｍｍ×３ｍｍ的Ｎｄ＾３＾＋：ＬｉＹ（ＢＯ３）３晶体。     

掺镱氟磷酸钙(Yb∶FAP)晶体的生长

用高频感应提拉法生长了掺Ｙｂ３＋氟磷酸钙（Ｙｂ∶ＦＡＰ）晶体,获得了理想的生长工艺参数．为消除晶体中通常存在的宏观缺陷,研究了晶体的退火条件．生长的晶体毛坯尺寸为２２ｍｍ×４５ｍｍ．对晶体进行了初步的位错观察,并估算了晶体的位错密度．     

掺镱氟磷酸钙（Yb：FAP）晶体的生长

用高频感应提法拉生长掺Ｙｂ３＋氟磷酸钙（Ｙｂ：ＦＡＰ）晶体,获得了理想的生长工艺参数,为消除晶体中通常存在的宏观缺陷,研究了晶体的退火条件,生长的晶体毛坯尺寸为φ２２ｍｍ×４５ｍｍ,对晶体进行了初步的位错观察,并估算了晶体的位错密度。     

深长内孔尺寸镀铬工艺的控制

我公司电镀车间的镀铬线 4个 130 0ｍｍ× 6 0 0ｍｍ× 2 0 0 0ｍｍ硬铬镀槽 ,对深长内孔零件的尺寸镀铬加工。零件材料为优质合金结构钢 ,内孔尺寸为 13ｍｍ× 12 0 0ｍｍ、 18ｍｍ× 5 0 0ｍｍ、 18ｍｍ× 70 0ｍｍ、 18ｍｍ× 10 0 0ｍｍ、 35ｍｍ× 35 0ｍｍ等 ,铬层厚度控制为 2 0～ 2 0 0 μｍ不等。多年来镀液稳定 ,全线工艺运转正常 ,生产良好。1　前处理对于镀硬铬件 ,前处理除去零件表面的氧化皮、锈蚀、污垢、毛刺 ,可以大大减少镀层的起皮剥落等疵病 ,预防雾状松散的镀层出现 ,减少镀层凹坑、麻点。1.1　工艺流程自检、记录汽…     

Elastic, Piezoelectric, and Dielectric Properties of 0.71Pb(Mg1/3Nb2/3)O3–0.29PbTiO3 Crystals Obtained by Solid-State Crystal Growth

Single crystals with the composition of 0.71Pb(Mg_1/3Nb_2/3)O₃–0.29PbTiO₃ (PMNT29) were grown using the solid-state crystal growth (SSCG) method. Compared with the conventional Bridgman grown crystals, the SSCG PMNT29 crystals were found to possess comparable piezoelectric, dielectric, and electromechanical properties ( d ₃₃∼1500 pC/N, ɛ^T ₃₃/ ɛ ₀∼5400 and k ₃₃∼90%), with the same Curie temperature ( T _C) and ferroelectric phase transformation temperature ( T _{R – T} ). The full set of elastic, piezoelectric, and dielectric material constants were determined by the resonance method for the SSCG grown PMNT29 crystals according to IEEE standards and compared with Bridgman grown crystals. The dielectric temperature behavior and the strain field characteristics were investigated, demonstrating excellent performance over the temperature range from room temperature to 95°C. Strain behavior at high electric fields was found to be different from Bridgman growth crystals and believed to be attributed to different domain structures.     

Effect of Firing Cycle on Structure and Some Dielectric and Piezoelectric Properties of Barium Titanate Ceramics

In the preparation of barium titanate ceramics for dielectric and piezoelectric applications, careful attention must be given to many factors which determine the ultimate performance of the ceramic. In this study structural differences were observed with the aid of electron micrographs as the time and temperature of firing were varied. At lower temperatures and shorter firing intervals crystals remained small, grain-boundary areas were relatively large, and there were numerous voids where several crystals joined. As the time and/or temperature were increased, crystals became larger with an improved grain-boundary condition that resulted in better structure. An optimum condition was soon reached beyond which rounding of edges at grain boundaries where several crystals joined became more pronounced. This caused an increase in the number of voids. Accompanying these changes, the 1-kc. dielectric constant, the piezoelectric constants (thickness mode), and coupling coefficients first improved, reached optimum values, and then declined slightly, but the resistance to depoling continually decreased as the crystal size increased. An experimental technique of rapid heating and cooling was used to prepare dense specimens of chemically pure barium titanate with relatively small average crystal sizes. Dielectric constants as high as 3000 with Q values of 80 were obtained for these high-density ceramics, accompanied by low effective piezoelectric constants and coupling coefficients.     

Dielectric and piezoelectric properties of Pb1-xBaxNb2O6 ferroelectric tungsten bronze crystals

Tungsten bronze single crystals in the Pb_1-xBa_xNb₂O₆ system were grown from a melt using the Czochralski technique. The dielectric, piezoelectric and pyroelectric properties were determined. The dielectric constant Ka and piezoelectric coefficient dI5 showed a strong enhancement upon approaching the tetragonal:orthorhombic morphotropic phase boundary as predicted by thermodynamic phenomenology. It is clear that crystals with a composition in the tetragonal phase field near this boundary will be of major interest for various piezoelectric device applications.     

Single Crystals of (PbxSr1-x) TiO3 Grown by Traveling Heater Method

A procedure is presented for growing single crystals of (Pb_xSr_1-x)TiO₃ by passing solvent zones through poly-crystalline rods of the same composition (THM). The solvent zone composition for homogeneous solid solution growth was chosen from the pseudoquaternary system 2PbO: 1B₂O₃-2SrO:1B₂O₃-PbTiO₃-SrTiO₃. Crystals with compositions throughout the complete range of PbTiO₃-SrTiOs solid solutions were grown. Emphasis was placed on crystal compositions near (Pb_0.25Sr_0.78) TiO₃ which have Curie temperatures just below room temperature. The dielectric constants, Curie temperatures, and optical properties of these single crystals are presented. Nonlinear dielectric and electrooptic behaviors are also demonstrated.     

Growth of (K0.5Na0.5)NbO3–SrTiO3 lead-free piezoelectric single crystals by the solid state crystal growth method and their characterization

Lead zirconate titanate (PZT) piezoelectric ceramics are commonly used in various applications, e.g. gas igniters, high-voltage generators and microbalances. However, due to increasing health and environmental concerns over their high lead content, lead-free piezoelectric ceramics are being developed. Lead-free piezoelectric single crystals offer superior performance over their polycrystalline counterparts but are difficult to grow by conventional methods. In this paper, (K_0.5Na_0.5)NbO₃–SrTiO₃ (KNN–ST) single crystals are grown for the first time by the solid state crystal growth (SSCG) method. 〈100〉 KTaO₃ single crystal seeds are buried in the center of pellets of pressed KNN-ST powder. The single crystal grows from the seed crystal during sintering at 1100 °C for 20 h. The grown single crystals contain porosity, which is incorporated from the matrix during growth. The effect of SrTiO₃ addition on single crystal growth behavior, chemical composition and structure is evaluated.     

Growth and characterization of large size lead-free ferroelectric K(Ta,Nb)O3 single crystal

Lead-free piezoelectric materials with excellent performance are greatly demanded for the environmental issues. The lead-free ferroelectric single crystals are therefore greatly concerned for their much higher piezoelectricity than the polycrystalline counterparts and the domain-tunable property. However, the growth of large size and high-quality lead-free ferroelectric crystals has always been a great challenge. In this work, a ferroelectric KTa_1-xNb_xO₃ (KTN) single crystal with an extremely large size of 25 × 25 × 37 mm³ was grown using the modified top-seeded solution growth method. The large size enabled us to carry out comprehensive investigations on the crystal. The complete sets of dielectric, piezoelectric, and elastic constants for the [001]_C-poled KTN crystal with quasi single domain state were determined. Results showed that the crystal exhibits high electromechanical coupling coefficients with k_t~0.642 and k₃₃~0.679. Furthermore, the orientation dependence of the piezoelectric, dielectric, and elastic properties was determined by the tensor matrix transformation technique, and the maximum d₃₃, , and k₃₃ were found along the polar direction [001]_C. This work not only provides important guidance for the growth technology of lead-free ferroelectric crystals but also offers essential datasets of lead-free alkali niobate system, which is of great importance for both theoretical studies and designs of electromechanical devices.     

Growth and characterization of l-glutamic acid and sodium sulphate doped tri glycine sulphate single crystal

Single crystal of tri glycine sulphate has been grown in the presence and absence of l-glutamic acid and sodium sulphate by slow evaporation growth. The grown crystal was analyzed by single crystal X-ray diffraction. FTIR studies were used to confirm the presence of functional groups present in the grown crystals. The optical absorbance studies show the cut off wavelength to be 235 nm. The phase transition temperature was found to be 50 °C from DSC analysis. The dielectric behavior was identified. The AC conductance of the grown crystal was plotted. PE loop measurement is taken.     

Ultrahigh-performance [001]-oriented porous PZT-5H single crystal grown by the solid state crystal growth method

Porous PZT-5H single crystals are grown by the solid state crystal growth (SSCG) method. The microstructure, phase structure and dielectric/piezoelectric properties are investigated for [001]-oriented porous PZT-5H single crystal. Evolution of phase structure with temperature is researched using in-situ temperature-dependent X-ray diffraction. The effect of pores on performance parameters is simulated using COMSOL Multiphysics® software. Ultrahigh piezoelectric coefficient d₃₃ of up to about 1700 pC/N and effective piezoelectric coefficient d₃₃* of up to about 3700 pm/V at 5 kV/cm are obtained. Moreover, the effective piezoelectric coefficient d₃₃* is stable around 1900 pm/V under 3 kV/cm and 5 kV/cm in the temperature range of 70–160 °C. Importantly, the sample possess an extremely large figure of merit g₃₃*d₃₃ (111 × 10⁻¹² m²/N), which is related to the presence of pores in the single crystal. This work expands the scope of PZT based single crystal and highlights their significant application possibilities in piezoelectric energy harvester, and actuator at high temperature.     

0-3型压电陶瓷/硫铝酸盐水泥复合材料的介电性能和压电性能

用压制成型法，以水泥为基体，铌镁锆钛酸铅(lead magnesium niobate-lead zireonate-lead titanate，PMN)陶瓷颗粒为功能体制备了水泥基压电复合材料。分析讨论了复合材料的压电性能和介电性能。研究了水泥水化龄期对复合材料压电性能的影响，并对其机理进行了初探。结果表明：随着PMN含量的增加，压电复合材料的压电应变常数d33和介电常数均增大；不像压电陶瓷或压电复合材料的压电性能随时问的延长而减弱，水泥基压电复合材料的压电性则是随着水泥水化龄期的延长而增加，当到达一定龄期后，压电性能趋于稳定。