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利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,详细研究了贵金属原子在Pt(111)表面的低能溅射现象.模拟结果显示:对于垂直入射情况,入射原子的质量对Pt(111)表面的溅射阈值影响不大.当入射原子的能量小于溅射阈值时,入射原子基本以沉积为主;当入射原子的能量大于溅射阈值时,溅射产额随入射原子能量的增加而线性增大;当入射原子能量达到200eV时,各种入射原子的溅射产额都达到或接近1,此时入射原子主要起溅射作用.溅射原子发射的角分布概率和溅射花样与高能溅射相类似.研究表明:与基于二体碰撞近似的线性级联溅射理论不同,当入射原子能量大于溅射阈值时,低能入射原子的溅射产额正比于入射原子的约化能量和入射原子与基体原子的质量比.通过对低能入射原子的钉扎能力分析,提出了支配低能溅射的入射原子反射物理机理.
The potential energy of noble metal atoms on Pt (111) surface was studied in detail by molecular dynamics simulations using the intermolecular interaction potential of the embedded atomic method. The simulation results show that the mass of incident atoms on Pt 111) sputtering surface has little effect on the surface when the incident atomic energy is less than the sputtering threshold, the incident atomic basic deposition; when the incident atomic energy is greater than the sputtering threshold, the sputtering yield with the incident atomic energy Increases and increases linearly; when the incident atomic energy reaches 200 eV, the sputtering yields of all kinds of incident atoms reach or close to 1, at this time, the incident atomic mainly plays the role of sputtering. The angular distribution probability of sputtering atomic emission and sputtering The pattern is similar to high-energy sputtering.The results show that, different from the linear cascade sputtering theory based on two-body collision approximation, when the incident atomic energy is greater than the sputtering threshold, the sputtering yield of low-energy incident atoms is proportional to the incident atomic energy And the mass ratio of incident atoms to matrix atoms.Analyzing the pinning ability of low-energy incident atoms, the physical mechanism of incident atomic reflection that dominates low-energy sputtering is proposed.