轻敲式原子力显微镜相位成像的理论和实验研究  

THEORETICAL AND EXPERIMENTAL STUDY OF THE PHASE IMAGING OF TAPPING MODE ATOMIC FORCE MICROSCOPY

作　　者：曾瑜 刘国林 关睿 魏征[1] ZENG Yu;LIU Guolin;GUAN Rui;WEI Zheng(School of Mechanical and Electrical Engineering,Beijing University of Chemical Technology,Beijing 100029,China)

机构地区：[1]北京化工大学机电工程学院,北京100029

出　　处：《力学与实践》2024年第5期930-937,共8页Mechanics in Engineering

基　　金：国家自然科学基金项目(No.11572031)资助。

摘　　要：原子力显微镜有多种成像模式,轻敲模式是最为常用的扫描方式。轻敲模式能获取样品表面的高度信息和相位信息,其中相位信息具有更多的价值,其能反应样品表面的物理性质。为了理解原子力显微镜的相位成像机理,本文分别使用振动理论和能量理论推导了相位的理论表达式,发现两种理论方法所得到的相位表达式在本质上是一致的,并由理论结果得知相位与背景耗散和激励频率直接相关。其中背景耗散品的存在会掩盖样品表面的信息,降低相位对比度;而激励频率也会对相位产生极大的影响。本文通过理论和实验分析,发现在扫描过程中存在一个使得相位对比度达到最大的最优激励频率。这些结果对于解释原子力显微镜的相位像,进而在实验中优化相位成像具有重要意义。Atomic force microscopy(AFM)has various imaging modes,and tapping mode is the most commonly used scanning approach.Tapping mode allows for the acquisition of both height and phase information from the sample surface,with phase information being particularly valuable as it reflects the physical properties of the sample surface.To understand the mechanism behind phase imaging in AFM,this study derived theoretical expressions for phase using both vibration theory and energy theory.It was found that the phase expressions obtained from these two theoretical methods are fundamentally consistent.The theoretical results revealed that phase is directly related to background dissipation and excitation frequency.The presence of background dissipation can mask information from the sample surface and reduce phase contrast,while the excitation frequency also has a significant impact on phase.Through theoretical and experimental analyses,this paper identified an optimal excitation frequency during scanning that maximizes phase contrast.These findings are crucial for understanding phase imaging in AFM,and consequently,optimizing phase imaging in experiments.

关 键 词：轻敲式原子力显微镜 相位成像机理 相位对比度 能量耗散 激励频率 

分 类 号：O657[理学—分析化学] TH742[理学—化学] O326[机械工程—光学工程]