A Mesoscopic Study of Ferroelectrics with Engineered Domain Configurations

Dan Liu - M.S. Thesis Defense
Advisor:  Dr. Jiangyu Li

Date:  Monday, May 10, 2004
Time:  10:00 a.m.
Place:  105 Othmer Hall

The macroscopic properties of ferroelectrics are determined by their microstructure. A mesoscopic study to determine the properties of ferroelectrics based on their microstructure analysis is carried out. In ferroelectric single crystal, there are numerous domains coexisting; In ferroelectric ceramics, there are numerous grains, each with distinct domain patterns. Our mesoscopic theory deals with the configurations of domain patterns, using the energy minimization approach. The macroscopic property of ferroelectric single crystal, which is calculated from our mesoscopic theory using homogenization theory, is consistent with the experimental observation. The macroscopic property of ferroelectric polycrystal, which is determined by not only the orientation distribution of grains in ceramics but also the domain patterns in each grain, is also calculated. The optimal domain configuration for enhanced functionality is also identified.