轻敲模式原子力显微镜相位、频移特性研究

Research on the characteristics of phase and frequency shift in the tapping mode of atomic force microscopy

原子力显微镜在轻敲模式下工作时,相位像相比于高度像能提供更多的样品信息,因此如何提供高分辨率的相位像成为理论和实验研究的重要内容。原子力显微镜其核心部件为微悬臂梁系统,在轻敲模式下将其简化为质量-弹簧-阻尼振动模型。采用经典振动力学理论分析该模型,可得到一种提高相位像分辨率的方法。结果表明,在探针-样品系统中,对于不同的品质因子,通过合理选择激振频率可使相位像分辨率达到最大。研究结果对操作者在实验中取得更高分辨率的相位图具有一定的参考意义。

When atomic force microscopy works in tapping mode,the phase image can provide more sample information than the height image.It is an important content of theoretical and experimental research for atomic force microscopy to provide high-resolution phase image.The core component of atomic force microscope is the micro-cantilever system,which can be reduced to mass-spring-damped vibration model in tapping mode.A method for improving phase image resolution can be obtained by analyzing the model using classical vibration mechanics theory.Theoretical analysis shows that the phase image resolution can be maximized by reasonably selecting the excitation frequency for the quality factors of different cantilever-sample system.The related research results have certain reference significance to the imaging theory and experiments of AFM.