退火与极化温度对尼龙11薄膜驻极体内陷阱能级分布的影响

用热释电技术研究了尼龙11薄膜驻极体制备过程中热处理与极化温度对驻极体陷阱能级分布的影响.结果显示，淬火驻极体的热释电流谱上存在四个空间电荷退陷阱电流峰，而在退火处理后则显示两个退陷阱电流峰.采用多点法对热释电流谱进行理论拟合可以将各个退陷阱电流峰分离并得到它们的陷阱深度参数.这些参数进一步表明，淬火尼龙11薄膜驻极体内存在四个空间电荷的陷阱能级，极化温度升高对它们的分布情况影响不大；退火处理后，陷阱能级减少为两个，且随着极化温度的升高，较浅的陷阱能级有明显向较深陷阱能级接近的趋势. 关键词： 尼龙11 薄膜驻极体 热释电 热处理     

GaAs薄膜的有效量子限制长度及其极化子特性

本文用分数维方法研究Al_xGa_1-xAs衬底上GaAs薄膜中的极化子特性, 提出了确定GaAs薄膜的有效量子限制长度的一个新方法, 解决了原来方法中在衬底势垒处有效量子限制长度发散的困难, 得到了Al_xGa_1-xAs衬底上GaAs薄膜中的极化子的维数和结合能. 关键词： 分数维方法 极化子 GaAs薄膜     

Ge2Sb2Te5非晶薄膜中超快载流子动力学的飞秒分辨反射光谱研究

利用飞秒时间分辨抽运-探测反射光谱技术研究了室温下Ge₂Sb₂Te₅非晶薄膜中载流子超快动力学及其激发能量密度依赖性.发现光激发后05 ps时间内,反射变化率降到最小值,然后开始迅速增加,在几个皮秒时间内达到大于初始反射率的新的最大值.反射率的减小量、增加量和增加速率均随激发能量密度的增大而增加.利用高密度等离子体的Auger复合及其感应的晶格加热模型较好地定量解释了反射率由最小到最大的快速变化过程,表明高密度等离子体的Auger复合加热 关键词： 抽运-探测光谱 2Sb₂Te₅非晶薄膜')" href="#">Ge₂Sb₂Te₅非晶薄膜 Auger复合 载流子动力学     

Influence of the e-beam irradiation and photo-oxidation aging on the structure and properties of LDPE-OMMT nanocomposite films

In this paper two systems, polyethylene (LDPE) and polyethylene/commercial organo-modified montmorillonite (LDPE/OMMT) nanocomposite, were subjected to e-beam irradiation at different doses and both the molecular modifications and mechanical properties have been investigated through solubility, FT-IR, calorimetric and tensile tests. Moreover, in some of the irradiated systems photo-oxidation aging was performed and its effects were studied. The results show an enhancement with irradiation of the positive effect of the nano-filler loading, related to the increase of the mechanical properties, due to the increase of the nano-filler polymer interaction.Nevertheless calorimetric and FT-IR data indicate that the well known reduction of LDPE/OMMT nanocomposite resistance to photo-oxidation ageing, with respect to LDPE, is amplified by ionizing radiation.     

基于Cu/SiO_x/Al结构的阻变存储器多值特性及机理的研究

采用氧化硅材料构建了Cu/SiOx/Al的三明治结构阻变存储器件.用半导体参数分析仪对其阻变特性进行测量,结果表明其具有明显的阻变特性,并且通过调节限制电流,得到了四个稳定的阻态,各相邻阻态的电阻比大于10,并且具有良好的数据保持能力.在不同温度条件下对各个阻态进行电学测试及拟合,明确了不同阻态的电子传输机理不尽相同:阻态1和阻态2为欧姆传导机制,阻态3为P-F(Pool-Frenkel)发射机制,阻态4为肖特基发射机制.根据电子传输机制,建立了铜细丝导电模型并对Cu/SiOx/Al阻变存储器件各个阻态的电致阻变机制进行解释.     

退火工艺对ICF靶用冷轧镍膜的影响

 为了满足惯性约束聚变（ICF）和状态方程（EOS）实验以及靶装配工艺的需要,在薄膜轧制过程中间以及轧制工艺完成以后需要对镍膜进行热处理来改善其组织结构和力学性能。对多辊轧机冷轧的方法制备的厚11 mm镍膜中间退火工艺进行了研究,根据确定的合适的退火工艺退火后继续轧制得到成品镍膜厚7 mm,表面粗糙度小于50 nm,基本满足目前状态方程实验对箔膜的要求。金相显微照片表明镍膜晶粒经500 ℃保温1 h退火由轧制前的条带状变为等轴晶;镍膜硬度经500 ℃退火后由4 GPa降低到了2.3 GPa左右;XRD衍射测试表明镍膜经500 ℃以上温度退火后,高角度的衍射峰开始出现,织构得到一定程度的改善。由此可以确定镍膜合适的中间退火温度为520 ℃保温1 h。     

硼膜制备工艺、微观结构及其在硼化镁超导约瑟夫森结中的应用

MgB_2材料具备临界转变温度较高、相干长度大、临界电流和临界磁场高等优点,被认为有替代Nb基超导材料的潜力.研究了不同温度下以化学气相沉积法制备的硼(B)薄膜的微观结构.实验结果表明:较低温度沉积的B先驱薄膜为无定形B膜,可以与Mg蒸气反应生成MgB_2超导薄膜;当沉积温度高于550?C时,所得硼薄膜为晶型薄膜;以晶型硼薄膜为先驱膜在镁蒸气中退火,不能生成硼化镁超导薄膜.利用晶型B膜的这一特点,成功制备了以晶型硼薄膜为介质层的硼化镁超导约瑟夫森结.     

薄膜介质层绕式Blumlein线理论与实验研究

对薄膜介质层绕式Blumlein线的特性参数进行了理论分析。采用Pspice软件对电路模型进行了计算,分析了开关电感、寄生电阻对负载输出波形的影响。结果表明:开关电感的存在使得负载波形前沿变缓,后延波形扭曲变差,寄生电阻会影响负载的电压输出效率。采用模拟软件对传输线中的电磁场分布进行了计算,结果表明薄电极边缘场畸变以及折叠弯曲部分的场变化是绝缘介质耐压必须考虑的因素。基于此理论分析,设计制作了一种新型薄膜介质Blumlein线,绝缘材料为聚酯薄膜,单层薄膜厚100μm,电极为厚50μm的铜皮,单元模块设计耐压50 kV。进行了三级模块串联叠加实验,充电25 kV,匹配负载输出60 kV,脉冲上升沿80 ns,脉冲宽度200 ns。     

离子束增强沉积VO2多晶薄膜的温度系数

用改进的离子束增强沉积方法和恰当的退火从V2O5粉末直接制备了VO2多晶薄膜.实验测试表明，薄膜的取向单一、相变特性显著、结构致密、界面结合牢固、工艺性能良好，薄膜的电阻温度系数（TCR）最高可达4.23%/K.从成膜机理出发，较详细地讨论了离子束增强沉积 VO2多晶薄膜的TCR高于VOx薄膜的TCR的原因.分析认为，单一取向的VO2结构使薄膜晶粒具有较高的电导激活能，致密的薄膜结构减少了氧空位和晶界宽度，使离子束增强沉积 VO2多晶薄膜结构比其他方法制备的VOx薄膜更接近于单晶VO2是其具有高TCR的原 关键词： VO2多晶薄膜 离子束增强沉积 热电阻温度系数     

Addition reaction and characterization of chlorotris(triphenylphosphine)iridium(I) on silicon(1 1 1) surfaces

Studies were performed to determine the chemical addition of a metal complex molecule, chlorotris(triphenylphosphine)iridium(I), on hydrogen passivated Si(1 1 1) surfaces to form a self-assembled monolayer (SAM). The iridium complex was synthesized prior to chemical addition, for which modified reaction conditions were chosen. Following addition, the silicon surfaces were characterized with X-ray photoelectron spectroscopy (XPS) and cyclic voltammetry (CV). The XPS results revealed that the surfaces consisted of the expected elemental percentages and that the iridium has a slightly higher success rate at attaching to oxide-free surfaces. XPS data also strongly indicate that the iridium complex remained intact upon chemisorption and did not decompose during the addition reaction. CV data show a difference between iridium treated surfaces and control samples. Hydrogen passivated wafers with iridium complex were much more conductive than those which were terminated with just an oxide or with an oxide and iridium complex. Furthermore, no free iridium reagent was detected as an additional feature in the current profile, indicating there was no physisorbed layer.