报告题目：Discovery and Design of Mesoscale Structures for Optimum and Novel Properties Guided by Phase-field Simulations
邀 请 人：吴勇军
Materials research is largely concerned with the study and manipulation of the spatial and temporal evolution of structural, magnetic, electric polarization, and chemical domains in a material as well as their responses to changes in environmental conditions. Much of the existing applications of phase-field method has been focused on modeling, reproducing, and understanding the evolution of experimentally observed materials microstructures during processing and in-service conditions or to test analytical theories. In order to establish phase-field method as one of the mainstream computational materials and physics methods for materials discovery and design, there is a need to focus our focus from purely “reproducing and understanding” experimental observations to “predicting mesoscale microstructures” and “guiding the synthesis and processing of materials to design their optimum properties and performances”. This presentation will discuss a few examples on our recent attempts to employ the phase-field method to not only to interpret and understand experimentally observed ferroic domain patterns but also to provide guidance to experimental synthesis and characterization to discover new mesoscale domain states of ferroic materials or achieve dramatically enhanced properties. Recent success examples of theory-guided design of materials include the discovery of polar vortex lattices, skyrmions, and unusual negative capacitances in ferroelectric superlattices, synthesis of record-high piezoelectricity in ferroelectric relaxor ceramics and single crystals, and the discovery of simultaneous near-perfect light transparency and ultrahigh piezoelectricity through AC poling.