Methods and systems for optimizing frequency modulation atomic force microscopy

摘要

Energy dissipation measurements in Frequency Modulation-Atomic Force Microscopy (FM-AFM) should provide additional information for dynamic force measurements as well as energy dissipation maps for robust material properties imaging as they should not be dependent directly upon the cantilever surface interaction regime. However, unexplained variabilities in experimental data have prevented progress in utilizing such energy dissipation studies. The inventors have demonstrated that the frequency response of the piezoacoustic cantilever excitation system, traditionally assumed flat, can actually lead to surprisingly large apparent damping by the coupling of the frequency shift to the drive-amplitude signal. Accordingly, means for correcting this source of apparent damping are presented allowing dissipation measurements to be reliably obtained and quantitatively compared to theoretical models. The methods are non-destructive and can be both easily and routinely integrated into FM-AFM measurements within vacuum environments where measurements exploiting prior art solutions cannot be performed.