报告时间：2024年9月27日下午3:00-4:30

报告人：Long-Qing Chen（The Pennsylvania State University）

报告地点：清华大学逸夫技术科学楼A205学术报告厅

邀请人：林元华老师

报告题目：Thermodynamics and Phase-field Method of Ferroelectric Crystals with Domains

报告简介：

The lecture discusses the thermodynamics and the phase-field method of ferroelectric crystals and their applications to modeling and predicting the stability of domain structures and their responses to mechanical and electric fields. It will start with the basic principles of classical thermodynamics by introducing a modern version of the first law of thermodynamics and apply it to obtain the fundamental equation of thermodynamics for homogeneous ferroelectric crystals. The relations of the fundamental equations of thermodynamics, Landau theory of ferroelectrics, and the thermodynamic properties will then be discussed, including the dielectric, elastic, piezoelectric properties. It will then be followed by the discussion on the thermodynamics of inhomogeneous ferroelectric crystals containing domain structures involving long-range elastic and electrostatic interactions and domain wall energy. The last part of the lecture will be focused on the applications of the phase-field method of ferroelectric domain structures. Examples will be presented to illustrate the application of the phase-field method to interpreting and understanding experimentally observed ferroelectric domain structures and to providing guidance to experimental growth of thin films and characterization to discover new mesoscale domain states of materials, achieve dramatically enhanced properties, and uncover hidden functionality.

报告人简介：

Chen is Donald W. Hamer Professor of Materials Science and Engineering, Professor of Mathematics, and Professor of Engineering Science and Mechanics at the Pennsylvania State University. He received his Ph.D. from MIT, M.S. from Stony Brook University, and B.S. from Zhejiang University. His main research interests include theory and computational model development for understanding phase transitions and microstructure development in ferroelectric oxides, structural metallic alloys, as well as 2D, quantum, and energy materials. For his accomplishments, he received Material Research Society Materials Theory Award, Guggenheim Fellowship, Humboldt Research Award, TMS John Bardeen Award, and IEEE-UFFC-S Distinguished Lecture Award. He is a Fellow of TMS, MRS, AAAS, APS, ASM, and ACerS and a Member of Academia of Europaea.