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1.
INTRODUCTIONThemicrostructureofthinfilmsplaysacru cialroleinawidevarietyofphysicalprocesses.Thereareclearevidencesthatmanyphysicalpropertiesofathinfilmvarydramaticallyasitsmicrostructurechanges (Hausetal.,1 987) .Forinstance,roughsubstratescanbeusedtofabric…  相似文献   

2.
The surface morphology and growth mechanism of an aluminum film system deposited on silicone oil surfaces by a vapor depositing method was investigated by scanning electron microscopy. It was found that the perpendicular fluctuation of the film's bottom surface was more remarkable than that of the film's top surface. Near the joint between the film on the silicone oil substrate and the film on the silicon wafer surface on which the silicone oil substrate rested, was a naturally formed anomalous wedge-shaped wrinkly structure with slopes of 10−4–10−5 rad, whose growth mechanism could be interpreted under the assumption of the thermal expansion behavior of the liquid substrates. Project supported by NSFC (No. 19874016) and the Special Fund of Zhejiang Provincial Natural Science Foundation for Young Scientists (Grant No. 1997RC9603).  相似文献   

3.
INTRODUCTIONThenatureofsubstrateshasacrucialeffectonboththemicrostructureofthefilmsandthegrowthmechanism (Hausetal.,1 987;Krugetal.,1 990 ) .Forinstance,thetopsurfacesofmetallicthinfilmsdepositedonsolidsubstratesgenerallyhavearoughstructure ,whichcanbedescribedb…  相似文献   

4.
采用真空蒸发方法在硅油表面制备了一种具有自由支撑边界条件的铜薄膜系统并研究了其成膜机理和带状有序结构。实验发现:此类铜薄膜的生长机制近似服从二阶段生长模型。进一步实验发现:铜分枝状凝聚体在大气中作无规扩散和旋转,直到在某处堆积或者连接。在该连续铜薄膜系统中,我们观察到了带状有序结构。该有序结构是由一系列长度基本一致而宽度不尽相同的平行键块组成。实验结果表明:该有序结构是在样品被取出真空腔之前,由于液体基底的收缩导致薄膜压应力而形起的。理论推测铜薄膜中可能同时存在一系列不同类型的正弦型内应力分布,而这种内应力分布最终导致带状有序结构的形成。  相似文献   

5.
利用辉光等离子体辅助热丝化学气相沉积法,制备硫掺杂n型金刚石薄膜,利用光学发射谱技术对其生长环境进行原位诊断,分析合成机理及生长的最佳条件。结果表明,合成金刚石薄膜的合成反应区中主要粒子为CH、CH+、活性H原子,提高工作气压和硫碳配比浓度有利于提高硫掺杂浓度,在低温条件下合成了高品质的硫掺杂n型金刚石薄膜。  相似文献   

6.
High resistance thin film chip resistors(0603 type) were studied,and the specifications are as follows:1 k? with tolerance about ±0.1% after laser trimming and temperature coefficient of resistance(TCR) less than ±15×10-6/℃.Cr-Si-Ta-Al films were prepared with Ar flow rate and sputtering power fixed at 20 standard-state cubic centimeter per minute(sccm) and 100 W,respectively.The experiment shows that the electrical properties of Cr-SiTa-Al deposition films can meet the specification requirements of 0603 type thin film chip resistors when the deposition time was about 11 min and deposition films were annealed at 500 ℃ for 120 min.The morphologies of Cr-Si-TaAl film surfaces were examined by scanning electron microscopy(SEM).The analysis suggests that Ta and Al may be distributed in CrSi2 film with mixed form of several structures(e.g.,bridge-like,capillary-like or island-like structures),and such a structure distribution is responsible for high film resistance and low TCR of Cr-Si-Ta-Al film.  相似文献   

7.
采用直流磁控溅射方法在硅油基底上沉积出具有自由支撑边界条件的金属银薄膜系统,研究了银薄膜在大气环境中的表面形貌演化规律及其物理机理。实验发现银薄膜在真空状态下基本稳定,但在大气环境中发生强烈的收缩效应,使得薄膜开裂,其表面覆盖率不断降低。分析表明这一动态演化过程基本满足指数衰减规律,并可用薄膜内应力的不断释放加以解释。随着银薄膜的不断收缩,薄膜表面可呈现出异常丰富的褶皱形貌:在薄膜边界附近呈现基本垂直于边界的直线状条纹结构;而在薄膜中间区域,将形成二次起皱的扭曲状花样和无序网格状褶皱形貌。从单轴应力和双轴应力理论的角度出发,对各类奇特的褶皱形貌进行了细致的分析和讨论。  相似文献   

8.
Aluminum nitride (AlN) thin films with high c-axis orientation have been prepared on a glass substrate with an Al bottom electrode by radio frequency (RF) reactive magnetron sputtering. Based on the analysis of Berg's hysteresis model, the improved sputtering system is realized without a hysteresis effect. A new control method for rapidly depositing highly c-axis oriented AlN thin films is proposed. The N2 concentration could be controlled by observing the changes in cathode voltage, to realize the optimum processing condition where the target could be fixed stably in the transition region, and both stoichiometric film composition and a high deposition rate could be obtained. Under a 500 W RF power of a target with a 6 cm diameter, a substrate temperature of 450 ℃, a target-substrate distance of 60 mm and a N2 concentration of 25%, AlN thin film with preferential (002) orientation was deposited at 2.3 μm/h which is a much higher rate than previously achieved. Through X-ray diffraction (XRD) analysis, the full width at half maximum (FWHM) of AlN (002) was shown to be about 0.28°, which shows the good crystallinity and crystal orientation of AlN thin film. With other parameters held constant, any increase or decrease in N2 concentration results in an increase in the FWHM of AlN.  相似文献   

9.
The structural characteristics and optical and electrical properties of molecular-beam-epitaxy (MBE) grown ZnS0.8Se0.2 thin films on indium-tin-oxide(ITO) glas substrates were investigated in this work. TheX-ray diffraction (XRD) results indicated that high quality polycrystalline ZnS0.8Se0.2 thin film grown at the optimized temperature had a prefered orientation along the (111) planes. The transmission electron microscopy (TEM) cross-sectional micrograph of the sample showed a well defined columnar structure with lateral crystal dimension in the order of a few hundred angstroms. Ultraviolet (UV) photoresponsivity as high as 0.01 A/W had been demonstrated and for wavelengths longer than 450 nm, the response was down from the peak response by more than 3 orders of magnitude. The thin ZnS0.8Se0.2 photosensor layer, with a wide energy gap and anisotropic electrical property, makes a transmission UV liquid crystal light valve (LCLV) with high resolution feasible. Project supported by the National Natural Science Foundation of China (No. 59910161981) and RGC grant from the Hong Kong Government Grant (No. NSFC/HKUST 35), China  相似文献   

10.
Pseudomonas aeruginosa strain (AS 1.50) and Bacillus subtilis strain (AS 1.439) from Ming lake were decomposed by photocatalytic nanostructure N-TiO2 thin films in a photo-reactor under UV irradiation. The different thickness nanostructure N-TiO2 thin films coated on mesh grid were prepared by sol-gel method and immobilized at 500 ℃ (films A) or 350 ℃ (films B) for 1 h in a muffle furnace. The results showed that N-TiO2 thin film B (8.18 nm thickness, 2.760 nm height and 25.15 nm diameter) has more uniform granular nanostructure and thinner flat texture than N-TiO2 thin film A (12.17 nm thickness, 3.578 nm height and 27.50 nm diameter). The bactericidal action of N-TiO2 thin film A and film B for Pseudomonas aeruginosa strain (AS 1.50) and Bacillus subtilis varniger strain (AS1.439) were investigated in this work. More than 95% of photocatalytic bactericidal efficiency for Pseudomonas aeruginosa strain (AS 1.50) and 75% for Bacillus subtilis strain (AS 1.439) were achieved by using N-TiO2 thin films-B for 70-80 rain of irradiation during the photo-bactericidal experimental process. The results indicated that the photo-induced bactericidal efficiency of N-TiO2 thin films probably depended on the characteristics of the films.  相似文献   

11.
本文研究了过滤式阴极电弧沉积方法获得的类金刚石薄膜.实验研究电弧的稳定性和探针电流与沉积参数的关系,并系统研究了膜层的性能.膜层的摩擦性能也得到了研究.  相似文献   

12.
MBE growth of ZnSxSe1−x thin films on ITO coated glass substrates were carried out using ZnS and Se sources with the substrate temperature ranging from 270°C to 330°C. The XRD σ/2σ spectra resulted from these films indicated that the as-grown polycrystalline ZnSxSe1−x thin films had a preferred orientation along the (111) planes. The evaluated crystal sizes as deduced from the FWHM of the XRD layer peaks showed strong growth temperature dependence, with the optimized temperature being about 290 °C. Both AFM and TEM measurements of these thin films also indicated a similar growth temperature dependence. High quality ZnSxSe1−x thin film grown at the optimized temperature had the smoothest surface with lowest RMS value of 1.2 nm and TEM cross-sectional micrograph showing a well defined columnar structure. Project supported by the National Science Council of PRC (No. 59910161981) and RGC grant from the Hong Kong Government under Grant (No. NS-FC/HKUST 35)  相似文献   

13.
Exchange coupling and magnetization reversal mechanism in two series of Co_xNi_(1-x)/CoO(30 nm)(x=0.2 and 0.4)bilayers are studied by vector magnetometer.Two components of magnetization are measured parallel and perpendicular to the applied field.At low temperatures,coercivity H_c∝(t_(FM))~(-n),n=1.5 and 1.38 for x=0.2 and 0.4,respectively,in agreement with the random field model.At room temperature,the coercivity is nearly proportional to the inverse FM layer thickness.In addition to the exchange field and the coercivity,the characteristic of the magnetization reversal mechanism was found to change with temperature.At temperatures below 180 K,magnetization reversal process along the unidirectional axis is accompanied only by nucleation and pinning of domain wall while magnetization rotation is also involved at high temperatures.  相似文献   

14.
A novel asymmetrical pitch system for rotary wing is presented. The pitch control characteristics are studied and analyzed. Because elastic linkage is a key part in whole asymmetrical pitch system, in order to obtain the variation of the elastic linkage deformation, an experimental platform mainly based on the device of micro aerial vehicles (MAVs) and a new control system mounted on TMS320LF2407 are designed. This control system has its compacted configuration and reliability. Finally, using this system to control the MAV for simulating the flying forward, experimental results show the MAV’s flight attitude can be controlled based on the variation of the elastic linkage. Project supported by the National Natural Science Foundation of China (Grant No.60605028), the National High-Technology Research and Development Program of China (Grant No.2007AA04Z225), the Shanghai Rising-Star Program (Grant Nos.07QA14024, 07QH14006), the Shanghai Shuguang Program (Grant No.07SG47), and the Shanghai Leading Key Laboratory of Mechanical Automation and Robotics Science Foundation (Grant No.ZZ0805)  相似文献   

15.
Two types of molecular and polymer devices employing (2-(4′-biphenyl)-5-(4““““““““-tert-butylphenyl)-1,3,4-oxadiazole) (PBD)and poly(N-vinylcarbazole) (PVK) as electron transport and hole transport materials, respectively, have been fabricated. The structures of these two devices are ITO/PVK( 70 nm)/PBD(60 nm)/A1 and ITO/PVK: PBD (1:1 by mass, 70 nm)/A1. The formation of exciplex is evident by comparing the electroluminescence (EL) of a bi-layer device and the photoluminescence (PL) of a PVK and PBD mixed film.The maximum emission energy of exciplex evaluated is consistent with the peak emission of EL. Blue emissions from both devices are obtained. The type of exicplex is interpreted based on the energy level diagram of the bi-layer device.  相似文献   

16.
A rice mutant with Yaponica 9522 cultivar background Oryza sativa extraordinary glume 1 (Oseg 1) was identified from the M2 mutant pool mutagenized by ^60Co γ-ray. Compared with wild type plants, Oseg 1 developed longer empty glumes and rudimentary glumes. In some Oseg 1 mutants, the number of stamens of flowers was reduced and leaf-like lodicules occurred, and excessive lemma/palea-like organ could be observed in some mutant spikelets. This indicated that OsEG1 could regulate the development of rudimentary glumes, empty glumes, lemma/palea, lodicules, and stamens. Genetic analysis indicated that Oseg 1 came from a single recessive genetic locus. To clone OsEG1 gene, F2 population was constructed by a cross between Oseg 1 (Japonica) and Guangluai4 (Indica). Using map-based cloning approach, OsEG1 was mapped on chromosome 4, between INDEL marker OS407 and WHM0466 with genetic distance of 2.0 cm and 1.0 cm, respectively. These results are useful for further cloning and functional analysis of the OsEG1 gene.  相似文献   

17.
INTRODUCTION Veselago (1968) showed that if both the permit- tivity ε and the magnetic permeability μ of a material are negative, the propagation direction of an elec- tromagnetic (EM) wave will be opposite to its energy flow direction. Such media are called left-handed materials (LHMs) since the electric field E, magnetic field H, and wave vector k in these media form a left-hand triplet of vectors, instead of a right-hand triplet observed in conventional materials. For a long time, …  相似文献   

18.
高温超导薄膜生长是研究超导现象和超导器件的基础,一直是凝聚态物理研究的一个重要课题。各种各样的薄膜生长方法都被应用于高温超导薄膜的生长研究。本文采用一种崭新的薄膜沉积设备———脉冲电子束沉积系统(PED)成功制备出了NCCO,LSCO高温超导薄膜,并通过优化沉积参数,获得了具有良好表面形貌和超导转变特性的高温超导薄膜。  相似文献   

19.
n-soliton-like solutions of three non-isospectral equations, the non-isospectral mKdV equation, the non-isospectral sine-Gordon equation and the non-isospeetral nonlinear Schroedinger equation were obtained by using the Hirota method.  相似文献   

20.
准自由支撑铝薄膜系统的制备及其特征表面形貌   总被引:1,自引:0,他引:1  
采用真空蒸发的方法在液体基底表面成功制备了具有自由支撑边界条件的金属铝薄膜系统,观察并研究了薄膜中的特征表面形貌。实验发现:铝薄膜中存在着由一块块近似为长方形的畴块连接而成的自薄膜边缘向薄膜内部区域生长的特征带状结构形貌;带状结构中畴块的最大长度和最大宽度均先随薄膜厚度的增加而增大,随后稳定变小。分析认为:这些现象是由于液体基底与固体薄膜之间的特征相互作用所致。  相似文献   

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