Project H – Stress Modulated Electromechanical Coupling of Lead-Free Ferroelectrics
Description / Outline
Despite the potential importance of lead-free ferroelectric materials for applications in the medical, aerospace, military, transportation, and energy sectors due to their promising electromechanical properties, there is a clear lack of information regarding the mechanical behavior as well as the influence of external mechanical fields on the electromechanical coupling, structural phase transitions, and system disorder, i.e., ergodicity. In particular, the influence of aliovalent and isovalent dopants on the electromechanical behavior has not been fully understood, in particular the effect of dopants and corresponding defect associates on the mechanical properties.
The aim of this project is to experimentally investigate the influence of lattice defects and stress on the electromechanical properties and crystal structure of lead- free ferroelectrics for energy conversion systems through a combination of macroscopic measurements and local structure characterization. In particular, x-ray fluorescence holography at SPring-8 will be used to provide 3D atomic images around specific elements, giving information on the local lattice distortions and atomic fluctuations around dopants in disordered systems. In addition, x-ray diffraction with resonant scattering, x-ray absorption fine structure, and inelastic X-ray scattering will be also be employed to understand local structure as well as phase transitions of lead-free ferroelectric materials.