We simulate the {100}-oriented diamond f/lm growth of chemical vapour deposition (CVD) under different models in C-H and C-H-Cl systems in an atomic scale by using the revised kinetic Monte Carlo method. The simulation results show that: (1) the CVD diamond film growth in the C-H system is suitable for high substrate temperature, and the film surface roughness is very coarse; (2) the CVD diamond film can grow in the C-H-Cl system either at high temperature or at low temperature, and the film quality is outstanding; (3) atomic Cl takes an active role for the growth of diamond film, especially at low temperatures. The concentration of atomic Cl should be controlled in a proper range.

The crystallization, corresponding to the fcc structure (with packing density p≈ 0.74), of smooth equal hard spheres under batch-wised feeding and three-dimensional interval vibration is numerically obtained by using the discrete element method. The numerical experiment shows that the ordered packing can be realized by proper control of the dynamic parameters such as batch of each feeding ξ and vibration amplitude A. The radial distribution function and force network are used to characterize the ordered structure. The defect formed during vibrated packing is characterized as well. The results in our work fill the gap of getting packing density between random close packing and fcc packing in phase diagram which provides an effective way of theoretically investigating the complex process and mechanism of hard sphere crystallization and its dynamics.

Electronic structure calculation was carried out for the hydrogen-terminated carbon cluster designed to model the {111}-oriented diamond surface, Cd (111).Using LDA method with local generalised gradient corrections, the subject of the calculation included the adsorption of single-carbon species and double-carbon species on an activated diamond surface. The results showed that: (1) Single-carbon species will more likely result in {111}-oriented CVD diamond film growth than double-carbon species, however, the role of double-carbon species should not be ignored; (2) The adsorption of single-carbon species on activated site makes the system more stable than that of double-carbon species. (3) Our computation result of CH3 adsorption on growth surface is in good agreement with that acquired both theoretically and experimentally.

We present a numerical method capable of reproducing the densification process from the so-called random loose to dense packing of uniform spheres under vertical vibration. The effects of vibration amplitude and frequency are quantified, and the random close packing is shown to be achieved only if both parameters are properly controlled. Two densification mechanisms are identified: pushing filling by which the contact between spheres is maintained and jumping filling by which the contact between particles is periodically broken. In general, pushing filling occurs when the vibration intensity is low and jumping filling becomes dominant when the vibration intensity is high.

It is shown that by properly controlling vibrational and charging conditions, the transition from disordered to ordered, densest packing of particles can be obtained consistently. The method applies to both spherical and nonspherical particles. For spheres, face centered cubic packing with different orientations can be achieved by monitoring the vibration amplitude and frequency, and the structure of the bottom layer, in particular. The resultant force structures are ordered but do not necessarily correspond to the packing structures fully. The implications of the findings are also discussed.