Investigation of EL2 Defect in 10 MeV Electron Irradiated Undoped Semi－insulating LEC GaAs

ＩｎｖｅｓｔｉｇａｔｉｏｎｏｆＥＬ２Ｄｅｆｅｃｔｉｎ１０ＭｅＶＥｌｅｃｔｒｏｎＩｒｒａｄｉａｔｅｄＵｎｄｏｐｅｄＳｅｍｉ－ｉｎｓｕｌａｔｉｎｇＬＥＣＧａＡｓＷｕＦｅｎｇｍｅｉ，ＳｈｉＹｉ，ＣｈｅｎＷｕｍｉｎｇ，ＷｕＨｏｎｇｗｅｉａｎｄＬａｉＱｉｊｉ（...     

Relationship between the Local Vibration Mode Characteristics and the Charge State of Carbon Acceptor in GaAs

The local vibration mode(LVM)of carbon acceptor in GaAs is studied by measuring directly the changein LVM absorption with a NIC-170 SX FT-IR spectrometer.The change in the charge state of carbon acceptorand the temperature dependence of the LVM absorption were investigated also.The contents of the impuritiesother than carbon were estimated by secondary ion mass spectrometry.It is observed that the frequency,thespectral form and the integrated absorption of the LVM are not affected by the change in charge state of car-bon acceptor.     

Spatial Distribution of EL2 Defect in Semi-insulating GaAs

ＳｐａｔｉａｌＤｉｓｔｒｉｂｕｔｉｏｎｏｆＥＬ２ＤｅｆｅｃｔｉｎＳｅｍｉ－ｉｎｓｕｌａｔｉｎｇＧａＡｓＲｕＱｉｏｎｇｎａ；ＬｉＧｕａｎｇｐｉｎｇａｎｄＨｅＸｉｕｋｕｎ（汝琼娜）（李光平）（何秀坤）（ＴｉａｎｊｎｇＥｌｅｃｔｒｏｎｉｃＭａｔｅｒｉａｌｓ...     

Correlation between the crystallography and morphology of proeutectoid Widmanstätten cementite precipitates

Electron backscatter diffraction was used in conjunction with deep etching to examine the relationship between the crystallography and three-dimensional morphology of cementite precipitates in an Fe–1.34 wt% C–13.1 wt% Mn steel. Orientation relationships (ORs) between more than 200 proeutectoid Widmanstätten cementite precipitates and the surrounding austenite were determined to be on or very near either the well-known Pitsch OR or the Farooque–Edmonds OR. Scanning electron microscopy of the same specimens after deep etching was used to determine the three-dimensional morphology of each of the precipitates for which an OR was determined. These precipitates could be identified as either monolithic plates or conglomerates of laths. Results show that monolithic plates consistently exhibit the Pitsch OR and conglomerates of laths have the Farooque–Edmonds OR, indicating that the precipitate morphologies are dictated by their orientation relationships.     

Correlation between Electronic Structures and Formability of Icosahedrai Quasicrystals in Aluminium-transition metal Binary Alloys

The relation between electronic structures and formability of icosahedral quasicrystals in Al-transition metal binary alloys isinvestigated systematically.It is found that the number of (s d) electrons in the transition metals and the parameter |Δ1| which isa measure of the relative bonding between Al and the transition metals are closely related to the formability of icosahedralquasicrystals.Two rules of thumb are derived from the experimental results for twelve Al-transition metal alloys.     

Correlation between liquid structure and γ2-phase precipitation of Cu-Al-Ni shape memory alloys

1　ＩＮＴＲＯＤＵＣＴＩＯＮＣｕ ｂａｓｅｓｈａｐｅｍｅｍｏｒｙａｌｌｏｙｓ (ＳＭＡ)ａｒｅｃｏｍ ｍｅｒｃｉａｌｌｙａｔｔｒａｃｔｉｖｅｓｙｓｔｅｍｓｆｏｒｔｈｅｐｒａｃｔｉｃａｌｅｘｐｌｏｉｔａ ｔｉｏｎｏｆｔｈｅｓｈａｐｅｍｅｍｏｒｙｅｆｆｅｃｔ (ＳＭＥ     

Sideband Absorption and its Effects on Temperature Dependence of Local Vibrational Mode Main Absorption Band for Carbon Acceptor in Gallium Arsenide

１－ＩｎｔｒｏｄｕｃｔｉｏｎＣａｒｂｏｎｉｓａｐｒｅｖａｉｌｉｎｇｒｅｓｉｄｕａｌｉｍｐｕｒｉｔｙｉｎｕｎｄｏｐｅｄｓｅｍｉｉｎｓｕｌａｔｉｎｇ（ＳＩ）ＧａＡｓｃｒｙｓｔａｌｓｇｒｏｗｎｂｙｔｈｅｌｉｑｕｉｄｅｎｃａｐｓｕｌａｔｅｄＣｚｏｃｈｒａｌｓｋｉ（ＬＥＣ）ｔｅｃｈｎｉｑｕｅ，ａｎｄｉｔｐｒｅｄｏｍｉｎａｎｔｌｙｏｃｃｕｐｉｅｓｔｈｅａｒｓｅｎｉｃｓｉｔｅａｓａｃｃｅｐｔｏｒＣＡｓ．Ｓｉｎｃｅｔｈｅｍａｓｓｏｆｃａｒｂｏｎａｔｏｍｉｓｍｕｃｈｌｉｇｈｔｅｒｔｈａｎｔｈａｔｏｆａｒｓ…     

Raman Study of Defects in SI－GaAs and Se－doped Epitaxial Layer Irradiated by 10 MeV Electrons

ＲａｍａｎＳｔｕｄｙｏｆＤｅｆｅｃｔｓｉｎＳＩ－ＧａＡｓａｎｄＳｅ－ｄｏｐｅｄＥｐｉｔａｘｉａｌＬａｙｅｒＩｒｒａｄｉａｔｅｄｂｙ１０ＭｅＶＥｌｅｃｔｒｏｎｓＷｕＦｅｎｇｍｅｉ，ＬｉＨａｉｆｅｎｇ，ＣｈｅｎＷｕｍｉｎｇ，ＣｈｅｎｇＧｕｎｇｘｕａｎｄＨ...     

Correlation between the oxide impedance and corrosion behavior of Zr−Nb−Sn−Fe−Cu alloys

The correlation between the oxide impedance and corrosion behavior of two series of Zr−Nb−Sn−Fe−Cu alloys was evaluated. Corrosion tests were performed in a 70 ppm LiOH aqueous solution at 360°C for 300 days. The results of the corrosion tests revealed that the corrosion behavior of the alloys depended on the Nb and Sn content. The impedance characteristics for the pre- and post-transition oxide layers formed on the surface of the alloys were investigated in sulfuric acid at room temperature. From the results, a pertinent equivalent circuit model was preferably established, explaining the properties of double oxide layers. The impedance of the oxide layers correlated with the corrosion behavior; better corrosion resistance always showed higher electric resistance for the inner layers. It is thus concluded that a pertinent equivalent circuit model would be useful for evaluating the long-term corrosion behavior of Zr−Nb−Sn−Fe−Cu alloys.     

Relation between Shot Peening Process and Fatigue Life in the Case of Hardening Steels

Nowadays, in the auto industry, the need for improvement of fuel efficiency is getting increased more and more in terms of the global warming, as well as the need of light-weighting of gears, transmission parts. Hence, we‘ve studied the relation between the shot peening working conditions and factors for improvement of gear‘s fatigue life, and also the relation between the factors for improvement and the fatigue life, applying shot peening to a gear of SNCM220. Also, we examined the relation between the fatigue life and arc height that is utilized as a substitute characteristic for shot peening working conditions, adding its observation here.     

热处理对大直径半绝缘砷化镓中EL2缺陷的影响

利用金相显微镜和微区红外测量技术分析热处理对液封直拉法生长的大直径半绝缘砷化镓(LEC SI-GaAs)单晶中深施主缺陷EL2的影响。结果表明,原生大直径SI-GaAs样品中EL2缺陷浓度沿直径方向的分布呈现中心区域较高、近中心区域最低、边缘区域最高的特点。500℃退火EL2缺陷浓度稳定,真空闭管并快速冷却条件下850℃以上退火时,EL2缺陷浓度随温度升高而下降。并分析了热处理对EL2缺陷的影响机理。     

Relation between EL2 Groupand EL6 Group in SI-GaAs

ＲｅｌａｔｉｏｎｂｅｔｗｅｅｎＥＬ２ＧｒｏｕｐａｎｄＥＬ６ＧｒｏｕｐｉｎＳＩ－ＧａＡｓＷｕＦｅｎｇｍｅｉ吴凤美（Ｄｅｐｏｒｔｍｅｎｔｏｆｐｈｙｓｉｃｓ，ＮａｎｊｉｎｇＵｎｉｖｅｒｓｉｔｙ，Ｎａｎｊｉｎｇ２１００９３，Ｃｈｉｎａ）ＺｈａｏＺｈｏｕｙｉｎ...     

Effect of As Interstitial Diffusionon on the Properties of Undoped Semi-insulating LECGaAs

NDSILECGaAs crystals are widely used assubstrates for the fabrication of high perform-ance GaAs illtegrated circuit by an ion imPlama-tion technique. In the fabricaton Process, post-implamation annaling must be used to actiVatethe imPlanation atoms. Considerable changescan, howevef, occur in the elechical prOPeftiesof SI substfates after annealing. For examPle,the SI substfate is converted to p-tyPe conduc-ting [l] or a thin p-tyPe conducting layer is for-med on the surface of the SI…     

高频红外吸收法测定贵金属催化剂中的碳、硫

采用HCS－140型红外吸收碳硫分析仪同时测定贵金属催化剂中的碳、硫含量。试验了助熔剂种类、用量、样品量对测定的影响,用异标校正测定了多种类型贵金属催化剂中的碳、硫。取得了满意结果,方法的相对标准偏差为0．2％－7．7％。     

ZrMn2和TiMn2的电子结构与成键特征

利用电荷离散变分Xα(SCC-DV-Xα)方法计算了ZrMn2和TiMn2及其氢化物的电子结构,分析了电子结构对吸氢性能的影响.结果表明:在ZrMn2氢化物中,H原子与Mn原子的成键作用强于H原子与Zr原子之间的相互作用;在TiMn2H中,H原子也是主要与Mn的3p轨道成键,但与Ti的3p轨道也有一定的相互作用;H与Ti的3p轨道的弱键作用减弱了H与Mn的3p轨道的相互作用;吸氢使ZrMn2的c轴比a轴更容易产生变化.     

Synthesis, characterization and microwave absorption property of doped polyaniline nanocomposites containing TiO2 nanoparticles and carbon nanotubes

As nanomaterial possessing moderate conductivity, magnetic and dielectric property, novel hexanoic acid (HA)-doped polyaniline (PAni) nanocomposites containing TiO₂ nanoparticles (dielectric filler) and carbon nanotubes, CNTs (magnetic fillers such as single-walled carbon nanotube, SWNT and multi-walled carbon nanotube, MWNT) were prepared by template free method. The PAni were characterized by UV, FTIR, X-ray diffraction (XRD), thermogravimetric (TGA) and scanning electron microscopy (SEM) analyses. Conductivity, magnetization, dielectric and microwave absorption properties of PAni were also investigated. The resulted nanorods/tubes as shown in SEM images clearly show that polymerization is proceeded in micelle/water interface through elongation. During template free method, TiO₂ and CNT exist in the center of Ani/HA micelle. The SEM images show that some of the CNT enwrapped with PAni layer indicate CNT are just packed underneath the PAni and never attacked by PAni. PAni/HA/TiO₂/SWNT with 20% of SWNT exhibits the best microwave absorption property (99.2% absorption) with reflection loss of −21.7 dB at 6 GHz due to its moderate conductivity (1.27 S/cm), magnetization (M_s = 1.01 emu/g), highest tan δ and heterogeneity.