8 - Piezoresponse force microscopy for functional imaging of organic ferroelectrics

Abstract

Over the past 2 decades, organic ferroelectrics—an umbrella term for polymer and low molecular weight compounds with electrically switchable polarization—have been generating a continuously growing interest in expanding our knowledge of ferroelectricity beyond the conventional order-disorder and displacive-type inorganic ferroelectrics. Significant efforts have been made to develop original methods to synthesize new organic ferroelectrics with the application-relevant physical properties on par with or exceeding those of their inorganic counterparts. For these materials, scanning probe microscopy (SPM) techniques have been widely used to characterize, map, and manipulate their properties at the nanoscale allowing an insight into their domain structure, surface charge and surface potential variations, local conductivity, and elastic and electromechanical constants. Among the SPM techniques, piezoresponse force microscopy (PFM) has been most widely adopted for nondestructive visualization of the ferroelectric domain structures and control of polarization orientation with sub-10-nm spatial resolution, and picometer per volt-level signal sensitivity. In this chapter, we review current status in the field of PFM application to investigation of organic ferroelectrics.