Continuing miniaturization of portable electronic and mechanical devices requires development of the novel nanoscale elements. This can be realized using functional materials, such as ferroelectrics. Ferroelectrics exhibit a unique set of the properties, including piezoelectricity, high non-linear optical activity, pyroelectricity and others, and can be used in a wide range of practical applications from non-linear optical converters to data storage and processing devices. However, functionality of ferroelectric materials is defined on the nanometer level, which requires using the nanoscale investigative techniques. Atomic Force Microscopy (AFM) is one of such paradigmatic tools allowing comprehensive investigations of the functional ferroelectric properties. However, the capabilities of AFM are limited in terms of characterization of chemical properties. The introduction of other, concomitant technique into the measurement setup can provide a solution to this shortcoming and enable correlated investigations of the functional properties along with the chemical information.
Here we used multimodal functional and chemical imaging based on a combination of AFM with time-of-flight secondary ion mass spectrometry (ToF-SIMS) for comprehensive characterization of the ferroelectric crystals and thin films. These studies demonstrated significant role of the surface and bulk chemistry on the polarization reversal, which is important for the understanding of fundamental principles of ferroelectrics and their practical applications.
This work was conducted at the Center for Nanophase Materials Sciences, which is a Department of Energy (DOE) Office of Science User Facility.