共查询到20条相似文献,搜索用时 187 毫秒
1.
用捕获膜技术和卢瑟福背散射(RBS)谱仪测定Ag靶在27keV Ar+离子轰击下的溅射原子角分布,从而确定不同剂量下Ag的溅射产额,并对其靶点表面形貌进行扫描电子显微镜(SEM)观察。结果发现,所有的角分布都呈over-cosine形状,但其溅射产额却随着表面形貌不同而不同。根据溅射产额Y与轰击离子入射角φ变化关系,讨论不同轰击剂量下溅射产额的差别,肯定了表面形貌是影响溅射产额的一个重要因素,并由此提出“表观产额”的新概念。
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2.
研究了正偏离Bragg定律,即计算Se(E)值高于实测Se(E)的二元系化合物靶的离子射程特性。文中应用“regular”观点引入了“双原子模型”,在二元化合物靶的射程计算中,不仅考虑相同“原子对”对离子的阻止本领S11(E),S22(E),而且考虑不同“原子对”对离子的阻止本领S12(E),S21(E)。文中还应用Berthelot关系,使S12(E)=S21(E)=(S11(E)·S22(E))1/2,则二元系靶的阻止本领及总的射程为NS(E)=1/2[(N1S11(E))1/2+(N2S22(E)1/2)]2, R=4/a[x-A1(arctg(2x+f)/△1/2-arctg(f/△1/2))-B1(ln(x+g)2/g2·e/(x2+fx+e)) -b/2 ln(x2+fx+e/e)。这里X=E1/2,E为离子注入能量,所有其它常数是与离子和靶的质量、原子序数有关的常数。结合文献[1]提出的R与Rp,Rp与△Rp的关系式,可计算得正偏离系统的投影射程Rp及其偏差量△Rp。并对各关系式的物理意义作了阐明。
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3.
用捕获膜技术和卢瑟福背散射(RBS)分析,测定Al-Sn多相合金在30keV Ar+离子轰击时Al和Sn的溅射原子角分布。溅射后的样品用扫描电子显微镜(SEM)进行观察,并用电子微探针分析仪(EPMA)对轰击样品(靶点)和未轰击样品作成分分析。结果表明,Al的溅射原子角分布近于cosine形状,而Sn却是over-cosine型角分布。本文给出一个按不同表面形貌特征划分的各元素富集区i进行叠加的产额表达式,Y(θ)=∑Yi(θ),解释了实验结果。
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4.
利用Larmor钟方法计算了一维复合势垒系统中的隧穿时间.从计算结果,对由Larmor钟所定义的Larmor时间在复合势垒中的有效性、可加性,以及它们与透射时间τT、反射时间τR、逗留时间τD的关系作了讨论.6个Larmor时间中,τxT,τxR,τyT和τyR都不是有效的时间量,它们不能为隧穿时间提供有效的描述,只有τyT和τyR满足可加性和判据τD=TτyT+RτyR,它们最有可能给出透射时间τT、反射时间τR.τyT,τyR与势垒的对称性有关,等式τyT=τyR是否成立与势垒是否对称有关.
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采用嵌入原子方法的原子间相互作用势,通过分子动力学模拟详细研究了以不同角度入射的低能Ni原子与Pt (111)基体表面相互作用过程中的低能溅射行为.结果表明:随着入射角度从0°增加到80°,溅射产额Ys和入射原子钉扎系数S的变化均可以根据入射角θ近似地分为以下三个区域:当θ ≤ 20°时,Ys和S几乎保持不变,其值与垂直入射时接近,溅射原子的发射角分布和能量分布也与垂直入射时的情
关键词:
分子动力学模拟
入射角
低能溅射 相似文献
7.
采用快电子和重粒子(N2+,N+,Nf)混合的Monte Carlo模型,研究了氮直流辉光放电等离子体金属表面氮化过程中.e-N2s及N2+-N2s两种碰撞离解过程产生的原子态粒子(N+,N)的产生率和氮化粒子(N+,Nf)轰击靶表面的能量、粒子数密度及入射角分布随气体温度的变化规律.结果表明,使阴极靶处活性粒子(N+,Nf)的能量高且粒子数密度大,存在一个最佳放电温度;粒子(N+,N)的产生率及在靶表面的密度数都随着放电气体温度的升高而减少;有大量中性快原子Nf在工件表面小角入射,且粒子(N+,Nf)角分布受温度的影响很小. 相似文献
8.
27keV Ar+离子束沿法向分别入射在BaF2单晶(111),(100)和(110)的晶面上,用捕获器方法和Rutherford背散射分析法测定了Ba原子的溅射角分布和溅射产额。结果发现不同取向的晶体表面,它们的溅射产额有明显差异。当用剂量为5×1017ion/cm2的Ar+离子分别轰击这三种晶面时,其溅射产额的顺序Y100>y111>y110.对已被上述剂量辐照过的晶面再作相同剂量轰击时,测得的溅射产额明显增大。这些结果被认为是由于在离子辐照过程中表面晶格受损逐步增大所致。
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用射频磁控反应溅射法在ZnS衬底上制备了GeC薄膜,研究了工艺参数对Ge靶溅射及GeC薄膜红外透射性能的影响.衬底温度较低时GeC薄膜中含有H,形成了CH2,CH3,Ge-CH3等,使薄膜产生红外吸收;随衬底温度升高,薄膜红外吸收明显减小.靶基距、射频功率、Ar:CH4气体流量比、总气压对靶面中毒及溅射影响较大,但对GeC薄膜红外吸收影响较小.靶面中毒严重时,所制备无氢GeC薄膜附着性能差,随靶中毒减弱薄膜附着性能变好.优化工艺后,在ZnS衬底上制备了附着性能良好的无氢GeC薄膜,其折射率约为1.78,薄膜中C的含量比Ge的大,二者主要形成了C—Ge键.所制备的GeC/GaP红外增透保护膜系对ZnS衬底有良好的增透效果.
关键词:
GeC薄膜
红外透射光谱
射频磁控溅射
XPS 相似文献
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H.R. Bürgi W. Grüebler J. Nurzynski V. König P.A. Schmelzbach R. Risler B. Jenny R.A. Hardekopf 《Nuclear Physics A》1979,321(2):445-456
Five quantities, σ0, iT11, T20, T21 and T22, have been measured for the elastic (, d) scattering from 60Ni at 9 and 12 MeV and from 90Zr at 10, 11 and 12 MeV over a wide angular range. Excitation functions for σ0 and T20 have been also measured at an angle of 175°(lab) in the approximate energy range of 6–13 MeV for both target isotopes. The experimental results, together with similar data published earlier for 15 MeV have now been analysed using the optical model with the complex central, spin-orbit and tensor TR potentials. Excellent fits are obtained for the angular distributions for all five measured quantities. The main features of the excitation functions are also well reproduced. Five of the optical-model parameters can be fixed. Three other parameters can be constrained by simple mass dependence functions. Further evidence for the presence of an imaginary component of the spin-orbit potential is supplied by the analysis of the present data. 相似文献
13.
本文在Thomas-Fermi势能基础上,导出了全射程R的解析解:R=2/a[E1/2-A1(arctg(2E1/2-f)/△1/2+arctg f/△1/2)+B1ln((E1/2-f)2)/(E-fE1/2+d) ·d/f2],其中A1,B1,f,d和△均为与离子及靶的质量、原子序数有关的常数。结合导出的η=R/(Rp)(Rp指投影射程)比值的双曲线函数关系 η=F(μ)[A2(μ)+(B2(μ))/(ε1/2+C)],和ω=Rp/△Rp(△Rp指投影射程的标准偏差)比值的线性关系ω=A3(μ)ε1/21/2+B3(μ),可简便而又准确地计算R,△Rp,Rp.这里F(μ),A2(μ),B2(μ), B3(μ)和A3(μ)为μ的代数函数,μ为离子与靶的质量比,C是经验常数.并对η等关系式的物理意义作了讨论。上述公式的计算结果与Gibbons的数值解结果及有关实验结果作了比较,表明可用于元素半导体如Si、二元化合物如GaAs以及三元化合物如SiO2等;既对较轻离子适用,也对重离子适用,具有一定的普适范围。 相似文献
14.
V. I. Leiman P. M. Valov V. M. Maksimov O. Yu. Derkacheva E. S. Markov 《Physics of the Solid State》2013,55(6):1258-1261
The processes of nonisothermal nucleation in the CuCl solid solution in glass with a negative jump of the nucleation temperature have been investigated using optical spectroscopy and exciton-thermal analysis. Two distributions of CuCl nanoparticles differing in the average radii R (2.3 and 14.0 nm) have been obtained for the temperature drop from T 1 = 700°C to T 2 = 500°C. The formation of two distributions of CuCl particles has been numerically simulated and the agreement between the experimental and calculated radius distributions of CuCl particles has been obtained. 相似文献
15.
P. M. Valov V. I. Leiman O. Yu. Derkacheva V. M. Maksimov E. S. Markov 《JETP Letters》2012,95(5):249-252
Processes of the formation of the double distribution of CuCl nanoparticles in glass in two-stage annealing have been analyzed.
The distribution of CuCl nanoparticles with the average radius R
1 = 14 and 18 nm appears in 20 and 40 min at temperature T
1 = 700°C in samples 1 and 2, respectively. By this time, the formation of new clusters ends, and only the growth of previously
formed clusters occurs (the second stage of nucleation). Then, the formation of the CuCl phase continues at T
2 = 500°C. A decrease in the temperature is accompanied by a decrease in the critical radius of particles of a new phase. For
this reason, the formation and growth of new CuCl nuclei begin again and the second distribution with a mean radius of 1 nm
or larger is formed. As a result, double distributions of CuCl nanoparticles with significantly different mean radii are formed
in samples 1 and 2. The concentration and mean radius of CuCl particles in distributions have been determined from the optical
absorption spectra of CuCl nanocrystals at 80 K in the wavelength range of 300–500 nm. 相似文献
16.
Differential cross sections for reactions of the true ternary fission of nuclei that was induced by cold polarized neutrons
were constructed with allowance of the effect that Coriolis interaction and the interference between fission amplitudes of
neutron resonances excited in fissile nuclei upon incidentneutron capture by target nuclei exerted on angular distributions
of prescission third particles (alpha particles, neutrons, or photons). It is shown that T -odd TRI- and ROT-type asymmetries for prescission alpha particles are associated with, respectively, the odd and even components
of the Coriolis interaction-perturbed amplitude of angular distributions of particles belonging to the types indicated above.
These asymmetries have angular distributions differing from each other and stemming from a nontrivial dependence of these
components on the neutron-resonance spins J
s
and their projections K
s
onto the symmetry axis of the nucleus involved. It is shown that angular distributions of prescission photons and neutrons
from reactions of the ternary fission of nuclei that is induced by cold polarized neutrons are determined by the effect of
Coriolis forces exclusively. Therefore, the emerging T-odd asymmetries have a character of a ROT-type asymmetry and are universal for all target nuclei. 相似文献
17.
The complex permittivities of poly(vinylidene fluoride)/poly(methyl methacrylate) (PVDF/PMMA) blends have been measured under variation of temperature T(20°-60°C), frequency v(5 Hz-300 kHz), and hydrostatic pressure p (0-260 MPa). The values can be represented by a master curve with the shift factors △p/△ log (v/Hz) = ?140 MPa at room temperature and △ (1 /T) /△ log (v/Hz) = ?2. 10?4 K?1 at atmospheric pressure. The dependence of the activation energy △E A on pressure p is then given by △E A=(100 + 0.02 MPa?1 p) kJ/mol. Furthermore, the results indicate that the β-relaxation of PVDF is due to motions in the crystal-amorphous interphase. The interactions between the two polymers, which are miscible at all compositions, disturb the correlations between the PVDF monomer units at that location as well as the mobility of the PMMA side group. 相似文献
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Hadron jets in e+e? annihilation will broaden at high energies due to gluon bremsstrahlung. With nonperturbative pT effects dying out rapidly, the basic features of hadron jets can be calculated in perturbation theory. We examine the pT distribution of secondarily produced hadrons. This is uniquely connected with the deviation from the 1 + cos2θ dependence of single particle inclusive distributions. We discuss what can be learned about the gluon fragmentation given the pT and/or angular distributions. A sum rule is derived which establishes a relationship between the average pT2 and αS. 相似文献
20.
在改装了的拉力试验机上,以不同的拉伸速率ε(0.79—18×10-5s-1)进行加、卸载试验,并用中间扭摆和四端电位法同时测量了Ni-49at%Ti合金丝在应力诱导I/C相变过程的内耗Q-1、模量M/M0、电阻率ρ/ρ0和应力-应变曲线。研究了应力循环和应变速率的影响。在Q-1-ε曲线上出现Q-1峰,而在f2-ε曲线上出现与之相对应的模量极小。内耗峰的高度Qp-1和模量亏损值均随ε增大而增大。根据界面动力学模型和内耗的实验数据,计算得应力诱导I/C相变过程界面的动力学关系为V=V*(△G—△GR)m,V*和m为动力学参数,△GR为相变过程中运动相界面所受的阻力,计算得△GR≈1cal/mol。讨论了内耗和模量亏损、软模效应之间的关系。
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