High-Throughput Scanning Second-Harmonic-Generation Microscopy for Polar Materials

The Materials Genome Initiative aims to discover, develop, manufacture, and deploy advanced materials at twice the speed of conventional approaches. To achieve this, high-throughput characterization is essential for the rapid screening of candidate materials. In this study, a high-throughput scanning second-harmonic-generation microscope with automatic partitioning, accurate positioning, and fast scanning is developed that can rapidly probe and screen polar materials. Using this technique, typical ferroelectrics, including periodically poled lithium niobate crystals and PbZr_0.2 Ti_0.8 O₃ (PZT) thin films are first investigated, whereby the microscopic domain structures are clearly revealed. This technique is then applied to a compositional-gradient (100-x)%BaTiO₃ -x%SrTiO₃ film and a thickness-gradient PZT film to demonstrate its high-throughput capabilities. Since the second-harmonic-generation signal is correlated with the macroscopic remnant polarization over the probed region determined by the laser spot, it is free of artifacts arising from leakage current and electrostatic interference, while materials' symmetries and domain structures must be carefully considered in the data analysis. It is believed that this work can help promote the high-throughput development of polar materials and contribute to the Materials Genome Initiative.