Nanoscale Characterization of Ferroelectric Materials via Piezoresponse Force Microscopy

Coupling between electrical and mechanical phenomena is very often in nature. Apparently, it underpins the functionality of materials and systems as diversified as ferroelectrics and multiferroics to electroactive molecules to biological materials. In ferroelectrics, electromechanical behavior is directly linked to polarization order parameter and hence can be used to study phenomena ranging from polarization reversal mechanisms, domain wall pinning, cross-coupled phenomena in multiferroics, to direct imaging of electron-lattice coupling. It may be said that electromechanical coupling is also a key component of many electrochemical transformations, in which changes in oxidation state are associated with the variation in molecular shape and bond geometry. Electromechanical energy conversion is an integral part of processes such as triboelectricity, cavitation, and sonoluminescence. It will not be an exaggeration to say that electromechanics, along with mechanics and transport, is one of the fundamental phenomena in nature. Therefore, it forms a basis for numerous device applications, and is thus directly relevant to virtually all existing and emerging aspects of materials and nanoscience. Recent years showed significant growth of interest towards nanoscal