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1.
滕华国  徐至展  胡畏  王炎森  方渡飞 《物理学报》1996,45(11):1788-1792
在扭曲波库仑玻恩交换近似下计算了类钠铜离子2p3s+e-→2p53s3l+e-(l=0,1,2)的内壳层激发截面.结合单组态近似和组态相互作用两种情况下计算的自电离分支比,计算了上述组态的激发自电离截面.结果表明,在入射电子能量为1090eV时,组态相互作用使2p53s3d总的激发自电离截面增大至单组态近似的近两倍;而使2p53s2组态的激发自电离截面减小为单组态近似的36%;2p53s3p组态的激发自电离截面只是略有下降 关键词:  相似文献   

2.
闻心怡  王耘波  周文利  高俊雄  于军 《物理学报》2011,60(9):97701-097701
采用射频磁控溅射法在Pt/TiOx/SiO2/Si基片上制备了以BaPbO3(BPO)为缓冲层的Pb(Zr0.52,Ti0.48)Nb0.04O3 (Nb掺杂PZT, PZTN)薄膜.通过调整BPO层厚度,为该PZTN薄膜引入了不同的张应力.当BPO层厚度分别为68 nm和135 nm时,PZTN薄膜呈现随机取向,采用2θ-s 关键词: PZT 准同形相界 掠射扫描方式 结构精修  相似文献   

3.
分别采用6-31G*,6-31G?*基组对线性ArCN分子的X2+,A2i,B2+,C2i,D2+和E2r 6个电子态进行了从头计算法开壳自旋限制Hartree-Fock(ROHF)计算。计算结果表明线性ArCN分子的电子态具有典型的准分子结构,从而可以肯定CN与稀有气体原子Rg(Ar,Kr,Xe)能够形成自由基准分子。对X2+,A2i的自旋非限制Hartree-Fock(UHF)计算证实较大的自旋污染不影响势能曲线的形状。 关键词:  相似文献   

4.
采用等离子体增强化学气相沉积技术沉积一系列处于不同生长阶段的微晶硅薄膜.通过同步辐射X射线掠角反射技术研究微晶硅薄膜的表面粗糙度随时间等的演化,探讨微晶硅薄膜的生长动力学过程及其生长机制.研究结果表明,在衬底温度为200 ℃,电极间距为2 cm,沉积气压为6.66×102 Pa,射频功率密度为0.22 W/cm2,氢稀释度分别为99%和98%的沉积条件下,在玻璃衬底上生长的微晶硅薄膜生长指数β分别为0.21±0.01和0.24±0.01.根据KPZ模型,微晶硅薄膜的生长机制为有限扩散生长. 关键词: X射线掠角反射 微晶硅薄膜 表面粗糙度 生长机制  相似文献   

5.
龙君彦 《物理学报》1994,43(5):717-724
假定重子中轻层子间不存在三体力,并把满足约束Pi2+U(x2)+mi2=0(i=1,2)的二质点组的相对论力学应用于重子的SU3模型,取U(x2)形为α+bx2,通过适当坐标平移,可以将重子中的内部运动等效为两个协变谐振子。采用Kustanheimo-Stiel变换(简称K—S变换),可将它们化为两个三维氢原子问题。这样,在求解中能 关键词:  相似文献   

6.
光学教程分析了棱镜产生最小偏向角的必要条件,但其讨论过程不易被初学者所理解,且没有涉及产生最小偏向角的充分条件.本文将对其做适当改进,使之更简明、更完善. 如图1所示,SB为入射光线,经棱镜折射后成为CS′,两光线夹角θ称为偏向角.由图1知: 按折射定律有: i1=arc sin(nsin i1), i′1=arc sin[ nsin(a- i2)],θ=arc sin(nsin i2)+arc sin[nsin(a-i2)]-a(2)(2)式表明,θ随i1的改变而改变,而偏向角有一最小值的必要条件是: …  相似文献   

7.
6 电偶极振子的Ec 线图图 2中F(r,π/2 ,t)图线的零点 ,极值点、拐点等反映了什么 ?为说明这些问题我们需先作电偶极振子的Ec 线图 .在 φ =φ0 (定值 )的平面内 ,Ec 线满足的微分方程是drEcr=rdθEcθ将式 ( 4)代入上式 ,消去相同因子 ,得dr2cosθ=rdθsinθ即 drr =2 cosθdθsinθ =d(sin2 θ)sin2 θ解上式得 1rsin2 θ=恒量 ( 1 4′)或 G(r,θ) =1krsin2 θ=K(恒量 )   ( 1 4 )式 ( 1 4 )中k仍为 wc,值得注意Ec 线形状不随时间变化 .用类似于求E线的作图法画出E…  相似文献   

8.
孙睿鹏  黄锡珉  邵喜斌  马凯  荆海 《物理学报》1996,45(12):2035-2040
通过测量扭曲液晶盒中的液晶分子的实际扭曲角及摩擦方向与液晶分子的界面指向矢之间的方位偏角,用自行建立的液晶方位表面锚定能的测量方法,测定了5CB液晶与摩擦的聚酰亚胺界面的锚定能及其温度依赖性,并用热力学理论进行了分析.实验结果表明,随着温度的增加液晶的表面锚定能E是减小的,从25.5℃时的5.0×10-5J/m2减小到35℃时的5.0×10-6J/m2;同时,外推长度de关键词:  相似文献   

9.
鲍诚光 《物理学报》1994,43(11):1745-1753
研究了硼的201(基态),2022e14e14个N=2共壳P态结构的定性特征,表明了电子关联对自旋极性的依赖,显示了各量子态对取向(相对于总角动量L)的偏爱,研究了它们的几何结构和内部运动模式,侧重探讨了量子力学对称性对微观系统的决定性效应。 关键词:  相似文献   

10.
王静  朱震刚  刘国东 《物理学报》1996,45(11):1782-1787
研究了[110]和[100]取向高纯铝单晶在6×10-4拉压疲劳应变振幅条件下的应力σm和内耗Q-1的变化,对不同阶段的位错组态作了详细的透射电子显微镜观察,并利用滑移几何的观点予以解释 关键词:  相似文献   

11.
Using molecular-dynamics simulation, we study sputtering and defect formation induced by 5 keV Xe+ ion impact on a Pt(1 1 1) surface at oblique and glancing incidence angles. Impact on a terrace produces yield maxima at ?=60-65° incidence angle towards the surface normal. Beyond 75-80°, no damage is produced due to projectile ion reflection. Impact on a dense-packed step, however, produces defects in sizeable numbers up to glancing incidence, ?=85°. The dependence of the yields on the incidence angle and distance of the impact point of the projectile to the step are discussed.  相似文献   

12.
The chromium and titanium oxynitride films on glass substrate were deposited by using reactive RF magnetron sputtering in the present work. The structural and optical properties of the chromium and titanium oxynitride films as a function of power variations are investigated. The chromium oxynitride films are crystalline even at low power of Cr target (≥60 W) but the titanium oxynitride films are amorphous at low target power of Ti target (≤90 W) as observed from glancing incidence X-ray diffraction (GIXRD) patterns. The residual stress and strain of the chromium oxynitride films are calculated by sin2 ψ method, as the average crystallite size decreases with the increase in sputtering power of the Cr target, higher stress and strain values are observed. The chromium oxynitride films changes from hydrophilic to hydrophobic with the increase of contact angle value from 86.4° to 94.1°, but the deposited titanium oxynitride films are hydrophilic as observed from contact angle measurements. The changes in surface energy were calculated using contact angle measurements to substantiate the hydrophobic properties of the films. UV-vis and NIR spectrophotometer were used to obtain the transmission and absorption spectra, and the later was used for determining band gap values of the films, respectively. The refractive index of chromium and titanium oxynitride films increases with film packing density due to formation of crystalline chromium and titanium oxynitride films with the gradual rise in deposition rate as a result of increase in target powers.  相似文献   

13.
A facile approach to manipulate the hydrophobicity of surface by controlled growth of standing Ag nanorod arrays is presented. Instead of following the complicated conventional method of the template-assisted growth, the morphology or particularly average diameter and number density (nanorods cm?2) of nanorods were controlled on bare Si substrate by simply varying the deposition rate during glancing angle deposition. The contact angle measurements showed that the evolution of Ag nanorods reduces the surface energy and makes an increment in the apparent water contact angle compared to the plain Ag thin film. The contact angle was found to increase for the Ag nanorod samples grown at lower deposition rates. Interestingly, the morphology of the nanorod arrays grown at very low deposition rate (1.2 Å?sec?1) results in a self-cleaning superhydrophobic surface of contact angle about 157° and a small roll-off angle about 5°. The observed improvement in hydrophobicity with change in the morphology of nanorod arrays is explained as the effect of reduction in solid fraction within the framework of Cassie–Baxter model. These self-cleaning Ag nanorod arrays could have a significant impact in wide range of applications such as anti-icing coatings, sensors and solar panels.  相似文献   

14.
The effect of size quantization of the reflection coefficient of electrons incident on a thin single-crystal film located on a substrate has been theoretically predicted. Two methods for observing this effect experimentally are proposed. In the first method, the variation in the intensity of the beam of specularly reflected electrons can be measured by varying the small glancing angle α of the electron beam with a particle energy on the order of 10 keV. In the second method, intensity oscillations of the diffracted beam as a function of the variation in the reflection angle β are measured in the case of a small fixed glancing angle α (on the order of 1°–3°). Thus, the second variant corresponds to studying the intensity distribution along streaks (reflexes) in the case of electron diffraction on a smooth surface. In the second case, the appearance of elastically scattered electrons along the streaks between diffraction reflexes is predicted. Their number (the beam intensity) varies periodically as a function of the angle β.  相似文献   

15.
The energy losses of a Cs+ion beam are theoretically studied during its glancing reflection from a smooth amorphous surface of a dielectric or a semiconductor and films made of these materials on a metallic substrate. The conditions of resonance fluctuation-electromagnetic interaction between neutralized Cs atoms and surface polaritons are considered for surfaces where the effects of interest seem to be the most significant. Calculations indicate that, at the optimized initial glancing angle and the Cs+ ion beam energy (ψin = 0.1–1.0 mrad, E 0 ~ 50–100 keV), the fluctuation-electromagnetic forces substantially contribute to the total energy losses and this contribution has characteristic dependences on the temperature, particle velocity, and material parameters.  相似文献   

16.
The glancing angle deposition (GLAD) technique was used to deposit ZnS films by electron beam evaporation method. The cross sectional scanning electron microscopy (SEM) image illustrated a highly orientated microstructure composed of slanted column. The atomic force microscopy (AFM) analysis indicated that incident flux angle had significant effects on the nodule size and surface roughness. Under identical nominal thickness, the actual thickness of the GLAD films is related to the incident flux angle. The refractive index and in-plane birefringence of the GLAD ZnS films were discussed, and the maximum birefringence Δn = 0.036 was obtained at incident flux angle of α = 80°. Therefore, the glancing angle deposition technique is a promising way to create a columnar structure with enhanced birefringent property.  相似文献   

17.
斜角入射沉积法制备渐变折射率薄膜的折射率分析   总被引:2,自引:0,他引:2       下载免费PDF全文
斜角入射沉积法是一种制备薄膜的新颖方法,它可以用来制备渐变折射率薄膜.本文首先探讨了膜料的沉积入射角为α,薄膜柱状生长倾斜角为β时的薄膜的填充系数;之后利用drude理论,分析研究了斜角入射沉积法制备渐变折射率薄膜的折射率与薄膜的入射角和生长方向的关系. 关键词: 斜角入射沉积 渐变折射率 填充系数  相似文献   

18.
The dynamics of ion-beam etching of test microstructures, simulating fragments of the surface structure of very large-scale modern integrated circuits, has been studied. Aluminum strip microstructures, 0.5 μm high and 1 μm wide deposited on the surface or embedded into SiO2, were used as test samples. 1 keV Ar+ ion beam 1 with a current density 0.5 mA/cm2, incident on the surface of a sample, rotating at a speed of 60 r/min, at an angle of 87°, has been used in the experiments. The surface morphology evolution was studied using atomic-force microscopy. The experiments demonstrate that physical ion sputtering at glancing incident angles can be used for the planarization of originally inhomogeneous structures. The achieved planarization degree allows one to use this method for defect detection in the metallization multilevel layers of very large-scale modern integrated circuits.  相似文献   

19.
Transparent polycarbonate samples were implanted with 1 MeV Ag+ ions to various doses ranging from 5 × 1014 to 3 × 1016 ions cm?2 with a beam current density of 900 nA cm?2. Modification in the structure of polycarbonate as a function of the implantation fluence was investigated using micro-Raman spectroscopy, glancing angle X-ray diffraction, and UV-Vis spectroscopy. Raman spectroscopy pointed toward the formation of graphite structures/clusters due to the ion implantation. UV-Vis absorption analysis suggests the formation of a carbonaceous layer and a drastic decrease in optical band gap from 4.12 eV to 0.50 eV at an implanted dose of 3 × 1016 ions cm?2. The correlation between the decrease in band gap and the structural changes is discussed.  相似文献   

20.
Abstract

Convoy electrons produced at glancing angle scattering of MeV HeH+ ions from an atomically clean (001) surface of SnTe crystal are observed. Energy spectrum of the convoy electrons shows a peak broader than that at scattering of atomic projectiles and the most probable energy of convoy electrons at HeH+ scattering is larger than those at scattering of isotachic He ions. This acceleration of convoy electrons is qualitatively explained by the force due to surface wake induced by Coulomb exploding fragment He2+ and H+.  相似文献   

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