轻敲模式下原子力显微镜的能量耗散机理研究  

Energy dissipation in tapping-mode atomic force microscopy

作　　者：樊康旗[1] 贾建援[1] 朱应敏[1] 

机构地区：[1]西安电子科技大学机电工程学院,陕西西安710071

出　　处：《西安电子科技大学学报》2007年第6期947-952,共6页Journal of Xidian University

基　　金：国家自然科学基金资助(10476019)

摘　　要：为研究原子力显微镜(AFM)在轻敲工作模式下的能量耗散机理,基于Hamaker假设和Lennard-Jones势能定律得到了原子与球体间的作用力.通过将球体与平面原子间的作用力等效为球体与平面间的粘着分布力,并结合经典弹性理论建立了一种新型的球体与平面粘着接触的弹性模型,根据所建模型得到了AFM针尖与样品表面间的粘着力随其间距的变化规律.仿真结果表明,粘着力随间距的变化曲线在AFM针尖趋近和撤离样品表面,即加载和卸载的两个过程中并不完全相同,产生了粘着滞后现象,而粘着滞后现象的出现表明AFM在轻敲工作模式中将耗散能量,因而,所建模型从理论上证实了AFM在轻敲工作模式下存在能量耗散现象.Based on Hamaker hypotheses and Lennard-Jones potential, the interaction between an atom and a sphere is obtained to investigate the energy dissipation in tapping-mode atomic force microscopy （AFM）. By considering the interaction between a sphere and an atom of a plane as the distributing adhesion force between a sphere and a plane, and combining with the elastic theory, a novel elastic model is established of adhesive contact between a sphere and a plane. With the adhesive model established, the variation of the adhesive force with the AFM tip-sample distance is obtained. Simulation results indicate that the variation of the adhesive force with the distance in the load process is different from that in the unload process, i. e. , the adhesive hysteresis is demonstrated, which is the indication of the energy dissipation. So the energy dissipation is shown by the proposed model in the tapping-mode AFM.

关 键 词：原子力显微镜 粘着模型 轻敲模式 能量耗散 

分 类 号：TN16[电子电信—物理电子学] TH724[机械工程—仪器科学与技术]