Ni原子倾斜轰击Pt(111)表面低能溅射现象的分子动力学模拟  

Molecular dynamics simulation of low-energy sputtering of Pt (111) surface by oblique Ni atom bombardment

作　　者：颜超[1] 段军红[1] 何兴道[1] 

机构地区：[1]南昌航空大学测试与光电学院,无损检测技术教育部重点实验室,南昌330063

出　　处：《物理学报》2011年第8期751-758,共8页Acta Physica Sinica

基　　金：南昌航空大学人才启动基金(批准号:EA200908182);航空科学基金(批准号:2009ZE56009);国家自然科学基金(批准号:50962011)资助的课题~~

摘　　要：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况类似;当θ≥60°时,Ys≈0,S≈0;在20°≤θ≤60°的范围内,钉扎系数呈现减小的趋势,溅射产额呈现先增大后减小的趋势,溅射原子的发射角分布和能量分布均与θ≤20°时的情况有一定的差异.通过对入射原子和被溅射原子运动轨迹的跟踪,分别给出了不同入射角度范围内的低能溅射机理及入射原子与基体表面的相互作用机理,斜入射与垂直入射时的低能溅射机理存在一定的差异,也不同于基于二体碰撞理论得到的溅射模型.The low-energy sputtering on Pt （111） surface by Ni atom at incident angle in a range of 0°— 80° （with respect to the direction normal to the surface） is studied by molecular dynamics simulations.The atomic interaction potential obtained with embedded atom method is used in the simulation.The dependence of sputtering yield,energy and angular distribution of sputtered particles as well as sticking probability of Ni atom on incident angle are discussed.The dependence of sputtering yield on incident angle θ can be divided into three different regions in θ,i.e.,θ ≤ 20°,20° ≤ θ ≤ 60°,and θ ≥ 60°.Based on sticking probability and movement of incident atom,physical mechanism of low-energy sputtering at oblique particle bombardment is suggested.When the incident angle θ is smaller than 20°,the reflection of incident atom by target atom dominates the sputtering process of surface atom,which is similar to the sputtering mechanism for the case of θ=0°.While for 20° ≤ θ ≤ 60°,the reflection of incident atom is no longer important for the low-energy sputtering.For the case of θ ≥ 60°,there occurs no sputtering.

关 键 词：分子动力学模拟 入射角 低能溅射 

分 类 号：O562.5[理学—原子与分子物理]