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1.
Indium nanorods are grown on silicon substrates by using magnetron-sputtering technique. Film morphologies and nanorod microstructure are investigated by using scanning electron microscopy, high-resolution transmission electron microscopy (HRTEM), and x-ray diffraction. It is found that the mean diameter of the nanorods ranges from 30nm to 100nm and the height ranges from 30nm to 200nm. The HRTEM investigations show that the indium nanorods are single crystals and grow along the [100] axis. The nanorods grow from the facets near the surface undulation that is caused by compressive stress in the indium grains generated during grain coalescence process. For low melting point and high diffusivity metal, such as bismuth and indium, this spontaneous nanorod growth mechanism can be used to fabricate nanostructures.  相似文献   
2.
薄膜生长的随机模型   总被引:16,自引:0,他引:16       下载免费PDF全文
利用Monte Carlo模型研究了薄膜生长初始阶段岛的形貌与基底温度之间的关系,同时还研究了它们与汽相粒子入射剩余能量之间的关系.模型中考虑了三种动力学过程:粒子入射、吸附粒子扩散和粒子脱附,与以前薄膜生长模型的不同之一在于把入射过程看作独立于其他过程,而扩散和脱附过程是相互关联的.结果表明随基底温度的升高,岛的形貌经历了一个从分散生长、分形生长到凝聚生长的变化过程.低温下随汽相粒子入射和剩余能量增加,岛的形貌也经历了同样的变化过程. 关键词:  相似文献   
3.
A simulation of the growth of an obliquely deposited thin film in a three-dimensional lattice was made using kinetic Monte Carlo method. Cu growth in three dimensions on a (001) substrate with high deposition rates has been simulated in this model. We mainly investigated the variation of three-dimensional morphology and microstructure offilms with incidence angle of sputtered flux. The relation of roughness and densities of films with incidence angle was also investigated. The simulation results show that the surface roughness increases and the relative density of thin film decreases with increasing incidence angle, respectively; the columnar structures were separated by void regions for large incidence angle and high deposition rate. The simulation results are in good agreement with experimental results.However, the orientation angle of columns is not completely consistent with the classical tangent rule.  相似文献   
4.
Uniformly distributed indium hillocks are grown on silicon substrates by dc magnetron sputtering. The morphologies and the microstructures have been investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction (XRD). From the TEM and SEM images, we find that, at the earlier stage, the grain coalescent process dominates. This coalescent process induces a larger compressive stress. We believe that the drive force for hillock growth comes from this compressive stress. Under this compressive stress, the grain locating in the middle of several grains are extruded from these grains, and then a hillock forms with the increasing deposition time. For low melting point and high diffusion coefficient metal, such as bismuth and indium, this spontaneous-hillock growth mechanism can be used to fabricate well aligned nanostructures.  相似文献   
5.
A Monte Carlo simulation (MCS) technique is used to simulate the cathode sheath region of a helium dc glow discharge. In such a simulation, a nonuniform electric field and a transverse uniform magnetic field are considered. When the magnetic field intensity increases from 0 to 800 G, all types of collision considered in this paper are enhanced. This result is in agreement with the experimental result. The results also show that with the increase of magnetic field intensity, the electron transport time, the electron density increase, and the electron mean energy decreases.  相似文献   
6.
A Monte Carlo simulation technique has been used to model the electron transport beharlot, especially the electron diffusion motion, in the cathode fall region of a glow discharge under the influence of a non-uniform electric field and a transverse magnetic field perpen-dicular to the cathode sheath electric field. Three types of collisions (elastic, excitation and ionization) are taken into account in our model. The electron free flying time is determined by the electron-neutral atom collision frequency. We focus attention on the electron diffusion distance and velocity. The electron-neutral atom collision processes and the electron drift velocity are also studied. The results indicate that with the increase of the magnetic field the electron diffusion distance increases and the electron diffusion velocity decreases. The results Mso show that the collision processes are enhanced by the magnetic field, this is in agreement with the experimental result. However, the axial magnetic field does not affect the electron transport behavior.  相似文献   
7.
直流辉光放电等离子体轴向动力学过程的研究   总被引:1,自引:0,他引:1       下载免费PDF全文
采用磁流体动力学理论,考虑了电子与中性粒子的非弹性碰撞,应用有限差分法研究了直流辉光放电氩等离子体的轴向动力学过程,得到了氩等离子体密度、输运速度、温度以及电位的轴向分布,发现了气体压强和电极间距的变化对阴极区的电子密度有较大的影响,而对阴极区的离子密度的影响甚微。 关键词:  相似文献   
8.
魏合林  张磊  刘祖黎  姚凯伦 《中国物理 B》2011,20(11):118102-118102
Uniformly distributed polycrystalline indium nanohillocks are synthesized on silicon substrates with Au catalyst by using the radio frequency magnetic sputtering technique. The results show that the Au catalyst plays a key role in the formation of indium nanohillocks. After thermally oxidizing the indium nanohillocks at 500 ℃ in air for 5 h, the indium nanohillocks totally transform into In2O3 nanohillocks. The energy-dispersive X-ray spectroscopy result indicates that many oxygen vacancies and oxygen-indium vacancy pairs exist in the In2O3 nanohillocks. Photoluminescence spectra under an Ne laser excitation at 280 nm show broad emissions at 420 nm and 470 nm with a shoulder at 450 nm related to oxygen vacancies and oxygen-indium vacancies at room temperature.  相似文献   
9.
利用Monte Carlo (MC)模拟技术研究了非均一的吸附原子与基底相互作用能在一定的生长条件下对超薄膜生长过程的影响.非均一相互作用能是由基底表面原子在垂直和水平方向上实际位置与理想晶格原子位置的偏差所造成.本文用高斯分布来表示这种非均一相互作用能.模拟结果表明:非均一相互作用能对超薄膜的生长过程及薄膜的形貌有显著的影响.这种影响同时受到生长条件的限制,在中等温度时相互作用能的非均一性对岛的个数、平均大小的影响最显著;温度的增加在一定程度上可抵御相互作用能的非均一性对薄膜生长的影响. 关键词: 薄膜生长 Monte Carlo 模拟 相互作用能  相似文献   
10.
沉积粒子能量对薄膜早期生长过程的影响   总被引:5,自引:0,他引:5       下载免费PDF全文
陈敏  魏合林  刘祖黎  姚凯伦 《物理学报》2001,50(12):2446-2451
利用Monte Carlo(MC)模型研究了能量粒子对薄膜生长的初始阶段岛膜的形貌和岛的尺寸的影响,沉积粒子的能量范围为:0—0.7eV.在模型中考虑了原子沉积、吸附原子扩散和蒸发等过程,并详细考虑了临近和次临近原子的影响.结果表明,在所采用的参量范围内不同的基底温度情况下,能量粒子的影响有很大的区别.低基底温度情况下,沉积粒子强烈地影响着薄膜的生长过程中,岛膜的形貌、数量和尺寸随能量粒子的能量增加而有很大的变化.分析表明,这些变化都是由于能量粒子的介入使得表面吸附粒子的扩散能力增强所致 关键词: 薄膜生长 Monte Carlo方法 扩散  相似文献   
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