Fast frequency sweeping in resonance-tracking SPM for high-resolution AFAM and PFM imaging.

A new resonance-tracking (RT) method using fast frequency sweeping excitation was developed for quantitative scanning probe microscopy (SPM) imaging. This method allows quantitative imaging of elastic properties and ferroelectrical domains with nanoscale resolution at high data acquisition rates. It consists of a commercial AFM system combined with a high-frequency lock-in amplifier, a programmed function generator and a fast data acquisition card.