Ultrasonic Methods in Contact Atomic Force Microscopy
In this chapter, techniques for materials characterization at the nanoscale that combine ultrasonics and atomic force microscopy (AFM) are presented. The focus is on dynamic methods in which ultrasonic excitations induce vibrations of the AFM cantilever. The methods considered are restricted to those in which the tip of the cantilever remains in contact with the specimen surface for the majority of the motion. Several aspects of coupled ultrasonic-AFM systems are examined, including the tip-sample interaction forces, the linear dynamics of the flexural and torsional modes, and the nonlinear dynamics of the flexural modes. Ways in which the dynamic behavior can be used for quantitative determination of sample stiffness and qualitative imaging of relative stiffness are then described. Both linear cantilever spectroscopy methods and nonlinear force curve methods are discussed and example results presented. Techniques such as these are expected to play a major role in nanotechnology research.
Joseph A. TURNER, Donna C. HURLEY
Atomic Force Microscopy, AFAM, Flexural and Torsional Vibrations, Linear and Nonlinear Vibrations, Materials Characterization, UAFM, UFM, Ultrasonics.