Resonance enhancement in piezoresponse force microscopy:: Mapping electromechanical activity, contact stiffness, and Q factor

Piezoresponse force microscopy (PFM) and spectroscopy of domain structure and switching dynamics at small excitation voltages require resonance enhancement of the surface displacements. The contact stiffness depends strongly on local elastic properties and topography resulting in significant variations of the resonant frequency. Moreover, the resonant response is determined both by the Q factor and the electromechanical activity. Here we develop a resonance-enhanced PFM that allows mapping of the local electromechanical activity, contact stiffness, and loss factor, thus avoiding limitations inherent to conventional frequency tracking. We anticipate that this method will be instrumental in imaging weakly piezoelectric materials and probing inelastic phenomena in ferroelectrics. (c) 2006 American Institute of Physics.