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Prefer-oriented and fine grained polycrystalline GaN films are prepared by plasma enhanced metal organic chemical vapour deposition on nucleation surfaces of freestanding thick diamond films. The characteristics of the GaN films are characterized by x-ray diffraction, reflection high energy electron diffraction and atomic force microscopy. The results indicate that the structure and morphology of the films are strongly dependent on the deposition temperature. The most significant improvements in morphological and structural properties of GaN films are obtained under the proper deposition temperature of 400°C. 相似文献
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《中国物理快报》2016,(10)
Silver films(Ag) and silver-gold films(Ag-Au) with thickness ~15nm are coated on Bk7 glasses through thermal evaporation.After doping gold of 5.2%,the grain size of the Ag film reduces from 13.6nm to 9.1nm,also the surface roughness decreases from 1.45 nm to 0.94 nm.A UV lamp is used as the irradiation light source to accelerate the corrosion process in the atmosphere.After 17 h irradiation,the pure silver film surface turns dark,and the transmittances reduce from 350 nm to 500 nm,while the Ag-Au film degrades much less,almost negligibly after UV radiation.Additional x-ray photoelectron spectroscopy and atomic force micrographs data are provided to show atomic content of Sims and their surface morphologies.It is suggested that small grain size and high packing density of alloy film prevent reaction of silver with oxygen in the atmosphere,which leads to high stability of the Ag-Au Elm. 相似文献
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通过热氧化氟化锌(ZnF2)薄膜的方法制备出氟掺杂的多晶ZnO薄膜,ZnF2薄膜是利用电子束蒸发方法沉积在Si(100)衬底得到的。利用X射线衍射和X射线电子能谱研究了ZnF2薄膜向ZnO的转变过程。实验结果表明,在400℃退火30min的条件下能够获得六方纤锌矿结构的ZnO:F薄膜。对ZnO:F薄膜的室温光致发光谱可以观察到位于379nm、半峰全宽为73meV的紫外发射峰,而相应于缺陷的深能级发射则完全猝灭。表明ZnO中残留的F能够有效地增强激子的发光,同时使缺陷发光强度明显降低。对F掺杂对ZnO的发光性能的影响进行了讨论。 相似文献
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Fabrication techniques of ultra-thin optical polarizing films using gold island films have been investigated for the near-infrared region. The polarizing films are fabricated by stretching the periodic multilayers consisting of gold island layers and glass layers. We have experimentally investigated the optimum fabricating conditions necessary to induce large optical anisotropy into the gold island layers and have formed submicrometer-thick polarizing films with an extinction ratio of ≥20 dB in a near-infrared region longer than 800 nm. These polarizing films could be useful micro-polarizers for fiber-embedded in-line optical devices, micro-optics, and hybrid integrated optics. 相似文献
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Yan-Bin Wang Chu-Feng Sun Qiong Su Rong-Min Wang 《Journal of Macromolecular Science: Physics》2013,52(10):2064-2074
Multiply-alkylated cyclopentanes (MACs) with different molecular structure were deposited on single crystal silicon wafers coated with a thin aminopropyltrimethoxylsilane (APS) film as an adhesive layer to form MACs-APS films. The thickness, wetting behavior and nano-scale morphologies of the films were characterized by means of ellipsometry, contact angle measurement, and atomic force microscopy (AFM). The friction and wear behaviors of the thin films sliding against a Si3N4 ball were examined on a UMT-2MT tribometer in a ball-on-disk contact mode. The worn surfaces of the MACs-APS films and the counterpart Si3N4 balls were investigated with a scanning electron microscope (SEM). It was found that the water contact angles on the MACs-APS film increased with the MACs alkyl chain-length. The MACs-APS film exhibited higher load-carrying capacity and better friction reduction and anti-wear behavior as compared with the APS film. This is suggested to occur because the APS acts as a strongly bonded lubricant phase and MACs as a mobile lubricant phase in the MACs-APS film. The increase of the chain-length of the alkyl substituent in the MACs compounds resulted in improved tribological properties of MACs-APS film. It is suggested that the longer alkyl chains are much more flexible and can dissipate the mechanical energy during the shearing process more easily than the short chain compounds. MACs with the longer chains have stronger chain-chain interactions and the larger MAC molecules have stronger intermolecular interactions, resulting in the good tribological properties of MACs-APS film. 相似文献
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薄膜的光谱发射率 总被引:1,自引:0,他引:1
钟迪生 《光谱学与光谱分析》2001,21(1):23-27
本文讨论了薄膜内的多次反射对低吸收薄膜光谱发射率的影响。这里推导出的薄膜发射率的表达式与薄膜厚度d和其光学常数n(λ)和k(λ)有关。在d→∞的特殊情况下,薄膜发射率与大块材料发射率相等。给出了实际数值评价及发射率与d、n(λ)和k(λ)相互关系的更为精确的数值结果。 相似文献
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Critical dynamics in film geometry is analyzed within the field-theoretical approach. In particular we consider the case of purely relaxational dynamics (Model A) and Dirichlet boundary conditions, corresponding to the so-called ordinary surface universality class on both confining boundaries. The general scaling properties for the linear response and correlation functions and for dynamic Casimir forces are discussed. Within the Gaussian approximation we determine the analytic expressions for the associated universal scaling functions and study quantitatively in detail their qualitative features as well as their various limiting behaviors close to the bulk critical point. In addition we consider the effects of time-dependent fields on the fluctuation-induced dynamic Casimir force and determine analytically the corresponding universal scaling functions and their asymptotic behaviors for two specific instances of instantaneous perturbations. The universal aspects of nonlinear relaxation from an initially ordered state are also discussed emphasizing the different crossovers occurring during this evolution. The model considered is relevant to the critical dynamics of actual uniaxial ferromagnetic films with symmetry-preserving conditions at the confining surfaces and for Monte Carlo simulations of spin system with Glauber dynamics and free boundary conditions. 相似文献
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For the testing of methods for morphological analysis of composite films, a computer experiment was suggested. Two models were prepared to study the possibility of at least partial reconstruction of 3D structures from their 2D projections or sections. The importance of some morphological characteristics for the reconstruction of size and/or spatial distribution of objects is shown in the paper. It illustrates the usage and significance of the integral transform method for the unfolding of the structures, too. 相似文献
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WANGJun-Ping DUANYi-Shi 《理论物理通讯》2005,44(1):160-164
We study the topological structure of the vortex system in a superfluid film. Explicit expressions for the vortex density and velocity field as functions of the superfluid order parameter are derived. The evolution of vortices is also studied from the topological properties of the superfluid order parameter field. 相似文献
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WANG Jun-Ping DUAN Yi-Shi 《理论物理通讯》2005,44(7)
We study the topological structure of the vortex system in a superfiuid film. Explicit expressions for the vortex density and velocity field as functions of the superfluid order parameter are derived. The evolution of vortices is also studied from the topological properties of the superfluid order parameter field. 相似文献
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Field Emission Properties of Ball-Like Nano-Carbon Thin Films Deposited on Mo Films with Accidented Topography
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Ball-like nano-earbon thin films (BNCTs) are grown on Mo layers by microwave plasma chemical vapour deposition (MPCVD) system. The Mo layers are deposited on ceramic substrates by electron beam deposition method and are pretreated by ultrasonically scratching. The optimization effects of ultrasonically scratching pretreatment on the surface micro-structures of carbon films are studied. It is found from field-emission scanning electron microscope (FE-SEM) images and Raman spectra that the surface structures of the carbon films deposited on Mo pretreated are improved, which are composed of highly uniform nano-structured carbon balls with considerable disorder structures. Field emission (FE) measurements are carried out using a diode structure. The experimental results indicate that the BNCTs exhibit good FE properties, which have the turn on field of 1.56 V/μm, and the current density of 1.0mA/cm^2 at electric field of 4.0 V/μm, the uniformly distributed emission site density from a broad well-proportioned emission area of 4 cm^2 are also obtained. Linearity is observed in Fowler Nordheim (F N) plots in higher field region, and the possible emission mechanism of BNCTs is discussed. 相似文献
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《中国物理快报》2016,(5)
P-type nitrogen-doped ZnO films are prepared successfully by in-situ thermal oxidation of Zn_3N_2 films.The prepared films are characterized by x-ray diffraction,non-Rutherford backscattering(non-RBS) spectroscopy,xray photoelectron spectroscopy,and photoluminescence spectrum.The results show that the Zn_3N_2 films start to transform to ZnO at 400°C and the total nitrogen content decreases with the increasing annealing temperature.The p-type films are achieved at 500℃ with a low resistivity of 6.33Ω·cm and a high hole concentration of+8.82 × 10~(17) cm~(-3),as well as a low level of carbon contamination,indicating that the substitutional nitrogen(N_O) is an effective acceptor in the ZnO:N film.The photoluminescence spectra show clear UV emissions and also indicate the presence of oxygen vacancy(V_O) defects in the ZnO:N films.The p-type doping mechanism is briefly discussed. 相似文献
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提出了一种新的电致变色薄膜的锂化方法,通过电子枪蒸镀锂单质,提高了锂的离化率,从而提高了锂化效果,采用此技术研制的全固态电致变色薄膜器件获得了较好的变色特性,透射式和反射式全固态电致变色薄膜器件的变色性能分别为50% ̄5%和70% ̄20%。 相似文献
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The magnetization of coupled ferromagnetic films is calculated by Green's function method. The coupling can either be ferromagnetic or
antiferromagnetic. For the latter case, a concept of pseudo-spin is
suggested to make calculation possible. A pseudo-spin is actually an
anti-spin with its properties being analogue to other known anti-particles
such as a hole. The decreasing of Curie point as the coupling strength
decays is computed. It is noted that with the same strength,
antiferromagnetic coupling has higher Curie point than ferromagnetic
coupling. 相似文献