High frequency piezoresponse force microscopy in the 1-10 MHz regime

Imaging mechanisms in piezoresponse force microscopy (PFM) in the high frequency regime above the first contact resonance are analyzed. High frequency (HF) imaging enables the effective use of resonance enhancement to amplify weak signals, improves the signal to noise ratio, minimizes the electrostatic contribution to the signal, and improves electrical contact. The limiting factors in HF PFM include inertial stiffening, deteriorating signal transduction, laser spot effects, and the photodetector bandwidth. Analytical expressions for these limits are derived. High-quality PFM operation in the 1-10 MHz frequency range is demonstrated and prospects for imaging in the 10-100 MHz range are discussed. (c) 2007 American Institute of Physics.