以扩散理论基础,建立以"基本微观过程"为核心的新模型,首次对存在表面活化剂时薄膜生长的微观过程进行KINETIC MONTE CARLO模拟。模拟发现,温度较低时沉积原子自身更容易聚集成核,这一反常效应是由于表面活化剂原子比沉积原...以扩散理论基础,建立以"基本微观过程"为核心的新模型,首次对存在表面活化剂时薄膜生长的微观过程进行KINETIC MONTE CARLO模拟。模拟发现,温度较低时沉积原子自身更容易聚集成核,这一反常效应是由于表面活化剂原子比沉积原子更容易被激活扩散造成的。活化层原子和沉积原子都会发生跨层间的扩散,交换比并非恒等于1,而是与温度、入射率、成膜厚度等多种因素有关。展开更多
The molecular dynamics(MD) method was used to investigate the displacement cascades with primary knock-on atom(PKA) energies of 2-40 keV at 100 and600 K.The migration energy of defects and their clusters was calculate...The molecular dynamics(MD) method was used to investigate the displacement cascades with primary knock-on atom(PKA) energies of 2-40 keV at 100 and600 K.The migration energy of defects and their clusters was calculated by nudged elastic band(NEB) method.Object kinetic Monte Carlo(OKMC) was used to simulate the evolution of defects in Ni under annealing.In each annealing stage,the recombination mechanism was discussed and evolution of the defects under different cascade conditions was compared.It was found that the defects generated in high-temperature cascades are more stable than those in the low-temperature cascades.In addition,almost all the defects are annihilated during annealing process at low PKA energy.At PKA energy of 20-40 keV,however,a large number of defects would remain after annealing.展开更多
文中针对银的晶格特征和银薄膜的生长特性,建立了基于KMC(Kinetic Monte Carlo)方法的银薄膜生长模型,模拟了单层Ag膜生长初期的表面形貌。在周期性基底且层间原子间采用交错排列的方式条件下,采用EAM(Embedded Atom Method)计算原子间...文中针对银的晶格特征和银薄膜的生长特性,建立了基于KMC(Kinetic Monte Carlo)方法的银薄膜生长模型,模拟了单层Ag膜生长初期的表面形貌。在周期性基底且层间原子间采用交错排列的方式条件下,采用EAM(Embedded Atom Method)计算原子间作用势,并针对金属Ag的晶格特征及其成膜特性进行建模,编程,实验。实验结果表明:在温度不变的情况下,随着覆盖度的增加,表面原子的数量增多,且出现二维岛状生长;岛的生长形貌经历了从分散到凝聚生长的过程;原子岛的数量减少,同时岛的尺寸在增大。展开更多
The paper suggests that E = mc<sup>2</sup> may be open to misinterpretation and that in this form it is not what Einstein advanced first. It is further suggested to return to the slightly less compact form...The paper suggests that E = mc<sup>2</sup> may be open to misinterpretation and that in this form it is not what Einstein advanced first. It is further suggested to return to the slightly less compact formula E = Kmc<sup>2</sup> where a < K < 1 which has the merit of accounting for the measured ordinary energy density of the cosmos (K = 1/22) and the conjectured missing dark energy density of the universe (K = 21/22) from the view point of economical notation.展开更多
文摘根据文献数据，拟合得到了水在二氧化钚表面的脱附活化能：0～0．5层为200．0kJ／mol，0．5～1层为135．0kJ／mol，1～2层为47．6kJ／mol，2～3层为43．8 kJ／mol，〉3层为41．1kJ/mol。利用这些参数采用动力学蒙特卡罗方法（kinetic Monte Carlo，KMC）定量研究了水在二氧化钚表面的吸附和脱附行为，计算得到几种常见的吸附曲线：吸附动力学曲线、热脱附谱、吸附等温线和吸附等压线，模拟结果和文献数据吻合较好，误差小于20％。
文摘以扩散理论基础,建立以"基本微观过程"为核心的新模型,首次对存在表面活化剂时薄膜生长的微观过程进行KINETIC MONTE CARLO模拟。模拟发现,温度较低时沉积原子自身更容易聚集成核,这一反常效应是由于表面活化剂原子比沉积原子更容易被激活扩散造成的。活化层原子和沉积原子都会发生跨层间的扩散,交换比并非恒等于1,而是与温度、入射率、成膜厚度等多种因素有关。
基金supported by the CAS Strategically Leading Program of the Chinese Academy of Sciences(XD02004140)the National Natural Science Foundation of China(Nos.51371080,11076012)
文摘The molecular dynamics(MD) method was used to investigate the displacement cascades with primary knock-on atom(PKA) energies of 2-40 keV at 100 and600 K.The migration energy of defects and their clusters was calculated by nudged elastic band(NEB) method.Object kinetic Monte Carlo(OKMC) was used to simulate the evolution of defects in Ni under annealing.In each annealing stage,the recombination mechanism was discussed and evolution of the defects under different cascade conditions was compared.It was found that the defects generated in high-temperature cascades are more stable than those in the low-temperature cascades.In addition,almost all the defects are annihilated during annealing process at low PKA energy.At PKA energy of 20-40 keV,however,a large number of defects would remain after annealing.
文摘文中针对银的晶格特征和银薄膜的生长特性,建立了基于KMC(Kinetic Monte Carlo)方法的银薄膜生长模型,模拟了单层Ag膜生长初期的表面形貌。在周期性基底且层间原子间采用交错排列的方式条件下,采用EAM(Embedded Atom Method)计算原子间作用势,并针对金属Ag的晶格特征及其成膜特性进行建模,编程,实验。实验结果表明:在温度不变的情况下,随着覆盖度的增加,表面原子的数量增多,且出现二维岛状生长;岛的生长形貌经历了从分散到凝聚生长的过程;原子岛的数量减少,同时岛的尺寸在增大。
文摘The paper suggests that E = mc<sup>2</sup> may be open to misinterpretation and that in this form it is not what Einstein advanced first. It is further suggested to return to the slightly less compact formula E = Kmc<sup>2</sup> where a < K < 1 which has the merit of accounting for the measured ordinary energy density of the cosmos (K = 1/22) and the conjectured missing dark energy density of the universe (K = 21/22) from the view point of economical notation.
