Automated Three-Dimensional Piezoresponse Force Microscopy for Polarization-Vector Mapping at the Nanoscale

Abstract

The functional properties of ferroelectric materials are strongly influenced by their polarization orientation; as such, precise characterization of polarization vectors is important to ferroelectrics research. Here, we develop a fully automated three-dimensional piezoresponse force microscopy (Auto-3DPFM) technique, which integrates all essential steps in interferometric PFM for 3D polarization vector characterization, including laser alignment, tip calibration and approach, image acquisition, polarization vector reconstruction, and visualization. The automation reduces the experimental burden of ferroelectric polarization vector characterization, while continual calibration ensures consistency and reproducibility of 3D polarization reconstruction. An algorithmic workflow is also developed to identify domain walls and calculate their characteristic angles via a spatial vector-angle-difference method, presenting one capability enabled by Auto-3DPFM and inaccessible through traditional PFM techniques. When integrated with machine learning and adaptive sampling strategies in self-driving labs, Auto-3DPFM serves as a valuable tool for advancing ferroelectric physics and microelectronics development.