Phase equilibria of Sn-In based micro-soldering alloys

The phase equilibria of Sn-In-X (X=Ag, Bi, Sb, Zn), the most basic information necessary for the development of Pb-free micro-soldering alloys, were studied using the CALPHAD method. Thermodynamic analyses for describing the Gibbs energies of the constituent phases were made by optimizing the obtained data on the experimental phase diagrams, and such data in the literature, including data on thermochemical properties. The present results combined with the thermodynamic database which was recently developed by our group [I. Ohnuma et al., J. Electron. Mater. 28, 1164 (1999)] provide various information on phase equilibria such as liquidus and solidus surfaces, isothermal and vertical section diagrams, mole fractions of the phase constitutions, etc., and thermodynamic properties such as activity, heat of mixing, surface energy, viscosity, etc., in multi-component soldering alloy systems including the elements of Pb, Bi, Sn, Sb, Cu, Ag, Zn, and In. Typical examples for the phase diagrams and thermodynamic properties of Sn-In-X ternary systems are shown. The application of the database to the alloy design for Pb-free solders is also presented.     

Metalorganic InP and Inx Ga1-x,Asy P1-y,on InP epitaxy at atmospheric pressure

We present a procedure for the MOVPE of InP as simple as the one currently used for GaAs. InP and InGaAsP alloys are grown on InP substrates using trimethy1indium (TMI), phosphine, trimethylgallium (TMG) and arsine. The choice of carrier gas is important ; a mixture of hydrogen and nitrogen allowed us to grow uniform layers over large areas at atmospheric pressure, without pyrolizing the phosphine or separating the input reactants. Preliminary characterization results are presented. Most information contained in this paper was presented at the 1983 Electron Materials Conference as paper Cl.     

Co_2O_3掺杂对0.965MgTiO_3-0.035SrTiO_3微波介质陶瓷性能的影响

采用传统电子陶瓷制备方法研究了Co2O3(1.5%～5.0%,质量分数)掺杂的0.965MgTiO3-0.035SrTiO3(MST0.035)微波介质陶瓷,分析了Co2O3含量对MST0.035陶瓷的烧结性能、晶相结构、显微形貌以及微波介电性能的影响。结果表明:Co2O3的掺杂促进了MST0.035陶瓷的烧结。随着Co2O3掺杂量的增加,陶瓷介电常数略有下降,谐振频率温度系数以及品质因数增加,同时中间相MgTi2O5逐渐减少直至完全消失。当Co2O3掺杂量为质量分数3.0%时,MST0.035陶瓷的烧结温度由1 380℃降低到1 290℃,其烧结所得的样品具有优良的微波介电性能:谐振频率温度系数τf=–2.53×10–6/℃,高的品质因数Q·f=19 006 GHz和介电常数εr=20.5。     

Electron Holography Studies on Narrow Magnetic Domain Walls Observed in a Heusler Alloy Ni50Mn25Al12.5Ga12.5

Peculiar magnetic domain walls produced in Heusler alloys, which have attracted renewed interest due to their potential application to actuators and spintronic devices, are studied here using electron holography. The observations reveal unexpectedly narrow magnetic domain walls, the width of which showed perfect agreement with that of the antiphase boundaries (APB, e.g., only 3 nm). While the results can be explained by the significant depression of ferromagnetism due to the local chemical disorder, the electron phase shift indicates that ferromagnetic correlation still remains in the APB region.     

Electrogenerated Chemiluminescence from a Phenyleneethynylene Derivative and its Ultrasensitive Immunosensing Application Using a Nanotubular Mesoporous Pt–Ag Alloy for Signal Amplification

Electrogenerated chemiluminescence (ECL) of a novel phenyleneethynylene derivatives [4,4’‐(2,5‐dimethoxy‐1,4‐phenylene)bis(ethyne‐2,1‐diyl) dibenzoic acid; P‐acid] possessing carboxylic acid groups at the para positions in aqueous solutions and its first immunosensing application are studied. Nanotubular mesoporous Pt–Ag alloy nanoparticles are first used to fabricate the ECL immunosensor as a signal amplification carrier. Absorption, photoluminescence, cyclic voltammetry, scanning electron microscopy, transmission electron microscopy, and electrochemical impedance spectroscopy are used as powerful tools to characterize P‐acid, Pt–Ag alloy nanoparticles, and the fabrication process of the immunosensor. P‐acid exhibits two ECL peaks at –1.07 (ECL‐1) and 0.64 (ECL‐2) V in air‐saturated pH 7.4, 0.1 M PBS containing 0.1 M KCl during the cyclic sweep between 1.51 and –2.67 V at 0.1 V s^?1; the ECL mechanism of these two ECL peaks is demonstrated. The electron‐transfer reaction between electrochemically oxidized P‐acid and tri‐n‐propylamine (TPrA) radical cation is also demonstrated to produce high ECL emissions and used to develop an ultrasensitive ECL immunosensor. In addition, a Pt–Ag alloy nanoparticles amplification carrier for protein ECL analysis is applied for improvement of the detection sensitivity. Thus, this ECL immunosensor exhibits high sensitivity, good reproducibility, rapid response, and long‐term stability.     

LF4、LF11、LF21、LY12铝合金的激光拼焊研究

采用５ｋＷ级横流ＣＯ_２激光器进行了ＬＦ４、ＬＦ１１、ＬＦ２１和ＬＹ１２铝合金的拼焊实验,研究了合金种类、辅助气体对焊接的影响,在金相显微镜下观察显微组织并测试其显微硬度。     

铝合金化学镀镍工艺研究与应用

报道一种在铝合金元件上实施化学镀镍的工艺方法。该方法包括在改进的锌酸 溶液中经二闪浸锌处理后,以碱性化学镀镍作底层,然后进行酸性化学镀镍,能在铝合金（ＬＹ１２ｃｚ、ＬＤ３１等）表面获得光亮的、具有优异附着力和良好的防腐蚀性能及其综合物理、化学特性的化学镀镍（Ｎｉ－Ｐ）层。     

Deposition of CoPtP films from citric electrolyte

Magnetically hard CoPtP (up to 40 μm thickness) films for MEMS application were deposited from citrate electrolyte and considered in terms of their composition, structure, magnetic characteristics and deposition conditions. Films containing 83-92 at.% (a/o) Co were deposited in the presence of NaH₂PO₂ in the electrolyte, with current efficiency of about 20% (deposition rate 10-12 μm/h). Coercivity 2.7-2.8 kOe and remanence 3.0 kG were achieved magnetizing in the direction normal to the film plane. According to XRD analysis, films seem to consist of hexagonal phase of CoPt solid solutions. Current efficiency, composition and morphology of the films, as well as their magnetic characteristics, were influenced by the electrolyte prehistory and total charge passed through the electrolyte in previous operation.     

超声共沉淀法合成锂离子电池正极材料

采用超声共沉淀法,合成尖晶石型掺杂锰酸锂Li1.05Co0.10Ni0.10Mn1.80O4前驱体,并使用三段热处理方式,制备出尖晶石产物。用粒度分布、XRD、SEM、EDS及电化学性能测试等对其进行表征。结果表明:与未处理试样相比,超声共沉淀法制备的产物的粒度分布变窄,体积比表面积由7.0116m2/cm3缩小至6.9789m2/cm3,晶格常数从0.822nm缩小至0.821nm,晶粒尺寸从67.41nm减小至57.78nm,晶形更加完整,颗粒均匀性更好。经装配成电池测定电化学性能,其充放电平台增长,比容量加大,循环性能更优越。     

硅单结晶体管γ射线辐照电阻变化规律研究

对在γ射线辐照条件下的单结晶体管基区阻值进行了多点测量和实时监测。结果发现：单结晶体管基区电阻值随γ射线辐照剂量的增加,具有先减小后增大的规律。对比国内外相关实验结果,从7射线与物质作用微观分析,证明位移效应是单结晶体管基区电阻在γ射线辐照下的主要效应,但它较电离效应具有一定滞后性。