Effect of texture on the piezoelectric properties of thin selenium films

A study was made of the sensitivity of the piezoelectric effect to the nature and development of the texture in thin (50–100 μ) selenium films. The texture of the ∞ type with the 〈11¯20〉 axis is shown to be piezoelectric. The magnitude of the piezoelectric effect depends on the texture, increasing with texture development. The texture with the 〈10¯12〉 axis is not piezoelectric.     

基底表面纳米织构对非晶四面体碳膜结构和摩擦特性的影响研究

本文利用离子束表面改性技术对基底表面进行不同时间的轰击, 形成不同规则的纳米织构, 对不同织构的变化规律进行了研究, 同时, 利用磁过滤真空阴极电弧技术, 在具有不同纳米织构的各基底上沉积相同时间的四面体非晶碳薄膜. 采用原子力显微镜对各基底的织构进行形貌分析, 结果表明, 高能粒子束的轰击对基底表面形貌有较大的影响, 根据离子束轰击时间的不同, 可以在基底表面形成各种不同规则的纳米织构, 轰击15 min后发现基底表面形成点阵纳米织构, 之后随着时间的增加, 基本维持点阵结构. 通过X射线光电子能谱仪和摩擦磨损试验仪对沉积在具有不同织构的基底上的ta-C薄膜进行测试, 研究表明, 基底表面纳米织构的非晶层结构引起薄膜内部sp³键的含量降低, 释放了薄膜的内应力, 同时发现基底表面纳米织构将ta-C薄膜磨损时间从不足10 min提高到约70 min, 有效提高了薄膜的耐磨性.     

Effect of texture dispersion on the effective biaxial modulus of cubic polycrystalline films

The effective biaxial modulus of fiber-textured cubic polycrystalline films with texture dispersion is estimated using Voigt-Reuss-Hill and Vook-Witt grain-interaction models. The orientation distribution function with Gaussian distributions of two Euler angles θ and ? is adopted to analyze the effect of texture dispersion degree on the effective biaxial modulus. Numerical results based on Cu and Cr fiber-textured films show that the distribution of angle ? has slight influence on the effective biaxial modulus of (0 0 1)-fiber-textured films if and only if the distribution of out-of-plane angle θ is narrow. Enhanced θ and ? distributions destroy the perfect fiber textures and as a result the films represent an evolution of ideal (h k l) fiber textures to nonideal or random textures with varying full widths at half maximums of θ and ?.     

Effect of solution concentrations on crystal structure,surface topographies and photoluminescence properties of ZnO thin films

Zinc oxide thin films were deposited on silicon substrates via hydrothermal method. Microstructures, surface topographies and optical properties of ZnO thin films were systematically investigated by X-ray diffraction, atomic force microscopy and fluorescence spectrophotometer. The mean grain size and surface roughness of the thin films decrease first and then increase with increasing the concentration of zinc nitrate hexahydrate. The photoluminescence spectra of ZnO thin films, excited by the 240, 320, 360, 380 and 400 nm excitation wavelength, were investigated in detail. Based on our analysis, it can be noted that mechanisms of the ultraviolet, violet and blue emissions are attributed to the transitions from the localized levels below the conduction band, zinc vacancy, interstitial zinc and extended interstitial zinc levels to the valance band, respectively. Blue–violet emissions of ZnO have great potential in light emitting and biological fluorescence labeling applications.     

Effect of pulsed magnetic field annealing on the microstructure and texture of grain-oriented silicon steel

The effect of pulsed magnetic primary annealing on the microstructure and texture of two-stage cold-rolled silicon steel is investigated. Specimens are annealed at 700 °C for 1 h under a 1 T pulsed magnetic field along different directions with respect to the sample coordinate system. Crystallographic orientation and grain size are identified by analyzing electron backscattered diffraction pattern. The effects of magnetic field treatment are related to the magnetic field direction. Based on the anisotropy energy of ferromagnetic material during magnetic annealing, a hypothesis is proposed. All of the experimental results in this work support the proposed model.     

Effect of surface spin waves on the magnetization of thin films

The theoretical calculation of the magnetization across the thickness of the film shows that it may be either lower or higher near the surface than at the centre of the film depending on the surface anisotropy. For intermediate surface anisotropy values the plots of magnetization vs distance from the surface show several extrema. The temperature dependences of magnetization show only small departures from the usual theoretical behaviour of thin films for the cases when surface spin waves are present. The given examples are calculated for uniaxial h.c.p. Heisenberg ferromagnet.     

Investigation on friction and wear behaviors of FeS films on L6 steel surface

Low temperature ion sulfuration technique was utilized to prepare the solid lubrication iron sulfide (FeS) film on the surface of die-steel AISI L6. The friction and wear behaviors of sulfurized L6 steel were investigated on the ring-on-block tester of MM-200 under dry sliding condition. Atomic force microscopy and scanning electron microscopy were adopted to analyze the morphologies and compositions of surfaces and wear scars of the FeS film. X-ray diffractometer was used to study the film phase structure. Scanning Auger microprobe was employed to detect the elements distribution with depth. The results showed that the tribological properties of sulfurized L6 steel were superior to that of the unsulfurized one.     

光学膜层缺陷分布特征对损伤行为的影响

 对多层介质反射膜与单层化学增透膜的损伤形貌、损伤过程及膜层的吸收特性进行了实验研究。结果表明：缺陷除了可以从其形态和光学特征分类外,还可以按缺陷的功能来划分,即以缺陷的损伤阈值来区分不同缺陷的抗激光损伤能力。通过对缺陷吸收率的测量,表明膜层的损伤阈值与缺陷的分布密度和热吸收具有显著的一致性。通过对损伤阈值分布曲线研究,可以有效地对缺陷进行分级判断,从而分析光学元件表面功能性缺陷的分布状况。     

The effect of dopants on the texture formation in MBE-grown polysilicon films

The texture of polysilicon films as a function of doping impurities and growth temperature was studied.     

光学膜层缺陷分布特征对损伤行为的影响

对多层介质反射膜与单层化学增透膜的损伤形貌、损伤过程及膜层的吸收特性进行了实验研究。结果表明：缺陷除了可以从其形态和光学特征分类外,还可以按缺陷的功能来划分,即以缺陷的损伤阈值来区分不同缺陷的抗激光损伤能力。通过对缺陷吸收率的测量,表明膜层的损伤阈值与缺陷的分布密度和热吸收具有显著的一致性。通过对损伤阈值分布曲线研究,可以有效地对缺陷进行分级判断,从而分析光学元件表面功能性缺陷的分布状况。     

Effect of surface composition on melting of thin InSb films

We demonstrate the possibility of melting thin (0.1–0.5 μm) InSb films directly in atmosphere under the protective layer of native oxides to obtain high mobility of majority carriers (up to 25 000 cm²/V s). The features of the film synthesis process based on thermal pulsed evaporation of InSb powder in vacuum are studied experimentally. Such a technique makes it possible to provide necessary compositional inhomogeneity of the deposited film for subsequent melting in air.     

On the magnetization distribution at the contact surface of two different thin films

On the basis of Valenta's model of ferromagnetic thin films the magnetization distribution in the proximity of the contact surface of two different films is calculated in the molecular field approximation.     

LB膜隔离层对表面增强喇曼散射的影响

本文首次利用LB膜作为分子—金属间的隔离层,考察了表面增强喇曼散射的电磁增强机理,监测了表面增强喇曼散射信号随隔离层厚度的变化。在银膜/LB膜/吡啶+氯化钾系中,实验结果表明,隔离层厚度为5nm时,表面增强喇曼散射效应仍然存在,但在15nm时已测不到其信号,实验支持了电磁增强机理。     

Effect of the reflection of underlying surface on sky radiance distribution

Sky radiance might be influenced by the multiple reflectance between the earth's albedo surface and the atmosphere. Based on the Lambert's law and the radiative transfer equation (RTE), a model is developed to calculate the additional sky radiance at wavelengths of 0.4-3 μm due to the reflectance contribution of the underlying surface. The iterative method is used to calculate sky radiance without the reflectance from underlying surface. The hybrid modified delta-Eddington approximation is used to compute the atmospheric reflection of the radiation from the earth's surface. An interaction factor is introduced to deal with the multiple reflectance between the atmosphere and the underlying surface. The sky radiance increment is evaluated for some different albedos of the earth's surface. The results show that the sky radiance increment rises rapidly while viewing zenith angle is near to 90°, and the larger the albedo of the earth's surface is, the more obvious this effect appears.