Enhancing Piezoresponse Force Microscopy with Dual-Frequency-Resonance-Tracking: A Practical Guide

This application note discusses the use of Dual-Frequency-Resonance-Tracking (DFRT) in Piezoresponse Force Microscopy (PFM). 

Piezoelectric materials generate an internal electric field when subjected to mechanical stress, and PFM is used to study and image electric polarization domains in these materials. Traditional PFM techniques involve applying an AC voltage at a fixed frequency, but DFRT uses multiple frequencies to enhance the signal and minimize crosstalk with surface topography. DFRT allows for high-fidelity PFM imaging, lower excitation voltage, and improved reproducibility in measurements.

Key learnings:

  • Piezoresponse Force Microscopy (PFM) is used to study ferroelectric materials' electric polarization domains and their applications in various fields.
  • DFRT in PFM involves exciting the cantilever at three frequencies, amplifying the piezoelectric response, and maintaining the main excitation frequency tuned to the contact resonance.
  • DFRT PFM provides high-fidelity images, reduces the need for manual frequency adjustments, and enhances signal-to-noise ratio (SNR).
  • DFRT is especially useful for characterizing ferroelectric switching in thin films and materials with low coercive fields.
  • Researchers can benefit from employing DFRT PFM to improve PFM measurements, including Switching-Spectroscopy PFM.