Formation Mechanism of Topological Bubble Domains in Bi₀.₅Na₀.₅TiO₃-Based Piezoelectric Thin Films

Release time：

2025-07-10

The high-efficiency bidirectional conversion capability between mechanical and electrical energy makes piezoelectric materials the core of next-generation smart systems. They are widely applied in nanogenerators, medical micro-devices, advanced electromechanical sensors, and drive innovative technologies such as piezoelectric-photocatalytic dye degradation and novel energy harvesting.The piezoelectric effect fundamentally originates from the coupled response between material polarization and mechanical stress, where domain structures (e.g., topological domains in ferroelectrics) serve as the microscopic carriers of polarization.In recent years, nanoscale topological domains (e.g., skyrmions, bubble domains) in ferroelectric thin films have become a research hotspot due to their unique physical properties.

The research team led by Jiwei Zhai at Tongji University, in collaboration with Huarong Zeng's group at the Shanghai Institute of Ceramics (Chinese Academy of Sciences) and Liqiang He's team at Xi'an Jiaotong University, has revealed the formation mechanism of topological bubble domains in Bi₀.₅Na₀.₅TiO₃ (BNT)-based piezoelectric thin films.Through combined experimental and computational approaches, we reveal that strong coupling between lattice distortion and oxygen octahedral tilting significantly enhances local structural heterogeneity, thereby inducing an increased density of bubble domains.These bubble domains feature low-angle domain walls (<5°) and high electric-field responsiveness, which effectively facilitate polarization rotation and thereby enhance piezoelectric performance.This study not only establishes the structure-property relationship of topological domains, but also provides a new paradigm for designing high-performance nanoelectronic devices based on domain engineering.

The research findings have been published in ACS Nano under the title 'Formation Mechanism of Topological Bubble Domains in Bi₀.₅Na₀.₅TiO₃-Based Piezoelectric Films'.The paper's first author is Yang Liu, a Ph.D. candidate at Tongji University. This research was supported by the National Natural Science Foundation of China (NSFC) and the National Key Research and Development Program of China.