High-Throughput Preparation of Size-Tunable BiFeO₃ Nanoislands with Topological Polar Structures for High-Density Memory

Topological polar structures found in ferroelectric nanoislands hold great promise for next-generation information storage devices due to their unique properties and potential for high-density data storage. However, traditional fabrication methods, such as electron-beam lithography, face significant challenges in achieving reproducibility and consistent domain structures with low cost, limiting their practical application. In this study, we proposed a high-throughput synthesis approach to enhance the research efficiency of topological ferroelectric domains in BiFeO3 nanoislands. By designing a temperature gradient during the film growth process, we successfully obtained self-assembled BiFeO3 nanoislands with various sizes (150–800 nm) as well as domain structures featuring temperature gradients. The topological ferroelectric domain configurations evolve gradually from Solomon rings-like to 4-fold, and eventually, multifold center-type domain with the nanoisland size increasing, while the smaller nanoisland shows a higher conduction. Our findings reveal the relationships between temperature, size, density, and ferroelectric domain configuration, providing valuable insights into the formation and growth mechanisms of BiFeO3 nanoislands and precise control of topological ferroelectric domains.