Thermodynamic consistent modelling of defects and microstructures in ferroelectrics

In: GAMM-Mitteilungen, Jg. 31 (2008) ; Nr. 2, S. 133-150
ISSN: 0936-7195
Zeitschriftenaufsatz / Fach: Bauwissenschaften
The paper describes the main phenomena associated with fatigue in ferroelectricmaterials due to defects and microstructural effects. An analysis the modelling on different length scales is presented. Starting from a thermodynamic analysis of the macroscopic material behavior other microscopic aspects are addressed. The introduction of an orientation distribution function allows for a computationally efficient extension of a single crystal model to realistic 3D structures. Additionally, the thermodynamic treatment of defects and domain wall motion is discussed to provide a better understanding of various micro-mechanisms. It is explained by the concept of configurational/driving forces, how defects influence each other and how the mobility of domain walls is reduced in the presence of defects.