AlxZn1-xO合金MSM光电探测器的研究

在Si衬底上磁控溅射制备AlxZn1-xO(AZO)合金薄膜,在其上真空蒸发Ni/Au叉指电极获得金属-半导体-金属(MSM)结构光电探测器.采用UV-Vis-Nir分光光度计测量AZO系列薄膜的光吸收特性,观察到AZO 合金薄膜的光学吸收带边随Al含量增加明显蓝移.测试AZO探测器的电流电压特性、时间特性和响应光谱发...     

Creep phenomena in lead-free solders

A critical review of data on microstructure and creep process activation energy values for a number of lead-free solder alloys like Sn-Ag; Sn-Bi; Sn-In was conducted. The review revealed a scatter in experimental data, which could not be explained by the dislocation creep mechanism only, even after the published data was corrected for Young’s modulus temperature dependence. An analysis of the data implies that possible origin of such a scatter is nucleation, accumulation and further growth of such internal defects as pores and microcracks during creep. It is shown that these processes may affect the measured steady-state creep rates, and may be one of the major reasons for the observed scatter in experimental data, and, therefore, must be taken into consideration in lead-free solder alloys’ creep studies.     

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。     

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.     

Effect of rare earth element addition on the microstructure of Sn-Ag-Cu solder joint

The effects of minimal rare earth (RE) element additions on the microstructure of Sn-Ag-Cu solder joint, especially the intermetallic compounds (IMCs), were investigated. The range of RE content in Sn-Ag-Cu alloys varied from 0 wt.% to 0.25 wt.%. Experimental results showed that IMCs could be dramatically repressed with the appropriate addition of RE, resulting in a fine microstructure. However, there existed an effective range for the RE addition. The best RE content was found to be 0.1 wt.% in the current study. In addition to the typical morphology of Ag₃Sn and Cu₆Sn₅ IMCs, other types of IMCs that have irregular morphology and uncertain constituents were also observed. The IMCs with large plate shape mainly contained Ag and Sn, but the content of Ag was much lower than that of Ag₃Sn. The cross sections of Cu₆Sn₅ IMCs whiskers showed various morphologies. Furthermore, some eutectic-like structures, including lamellar-, rod-, and needle-like phases, were observed. The morphology of eutectic-like structure was related to the RE content in solder alloys. When the content of RE is 0.1 wt.%, the needle-like phase was dominant, while the lamellar structure prevailed when the RE content was 0.05 wt.% or 0.25 wt.%. It is suggested that the morphology change of the eutectic-like structure directly affects the creep properties of the solder joint.     

Cobalt Assisted Synthesis of IrCu Hollow Octahedral Nanocages as Highly Active Electrocatalysts toward Oxygen Evolution Reaction

Development of oxygen evolution reaction (OER) catalysts with reduced precious metal content while enhancing catalytic performance has been of pivotal importance in cost‐effective design of acid polymer electrolyte membrane water electrolyzers. Hollow multimetallic nanostructures with well‐defined facets are ideally suited for saving the usage of expensive precious metals as well as boosting catalytic performances; however, Ir‐based hollow nanocatalysts have rarely been reported. Here, a very simple synthetic scheme is reported for the preparation of hollow octahedral nanocages of Co‐doped IrCu alloy with readily tunable morphology and size. The Co‐doped IrCu octahedral nanocages show excellent electrocatalytic activity and long‐term durability for OER in acidic media. Notably, their OER activity represents one of the best performances among Ir‐based acidic OER catalysts.     

激光熔覆镍基和钴基自熔合金的研究

本文采用镍基、钴基自熔合金通过激光熔覆获得性能优良的合金覆层,改善了叶片的耐磨性、耐蚀性,达到了提高使用寿命达10倍以上的目的。     

激光熔覆Co基合金温度场的数值模拟

为了分析Co合金熔覆的温度场,采用有限元法建立了低碳钢表面上激光熔覆预置钴基合金粉末过程的3维模型,考虑温度变化对热物理参量的影响以及表面对流换热和辐射散热等影响因素,使用SYSWELD软件对激光熔覆过程中的温度场进行了分析,并进行了验证。结果表明,激光熔覆过程中的温度场变化是由非稳态到稳态的过程,光斑附近等温面较为密集,远离光斑处等温面较稀疏;在其它工艺参量不变的情况下,扫描速率为5mm/s时熔覆过程的稀释率为8.26%,可以获得良好的冶金结合;利用SYSWELD软件的校核功能,获得了扫描速率为3mm/s和4mm/s时熔覆过程中较为合适的功率分别为1.6kW和1.87kW。研究结果对工艺参量的优化和控制熔覆层稀释率提供了借鉴和指导作用。