Collaborative Research: FRG: Local Dynamic Origins of Relaxor Ferroelectricity

Pennsylvania State Univ University Park, University Park PA

Investigators

Abstract

Our focused research group with members from the University of Pittsburgh and Pennsylvania State University will attempt to understand the physical basis of "relaxor" ferroelectricity. Our investigations will explore the boundary between the relaxor phase and other parent phases. Both single crystal bulk materials and MBE-grown thin films will be investigated. We will use novel measurement techniques that simultaneously probe both spatial and temporal behavior of relaxors. The proposed experiments will infuse much-needed empirical constraints into theory. The impact of this work will be both fundamental and practical. Relaxor behavior is prevalent in a wide class of ferroelectric materials, and is poorly understood. At the same time, relaxor single crystals can exhibit large, non-hysteretic strains >1%, electromechanical coupling >90% and outstanding dielectric and polarization values, performance that far exceeds most proper ferroelectrics. The cross-disciplinary nature of this research effort, involving a strong coupling of physics and material science, will enhance the experiences of students majoring in either discipline. Our focused research group will attempt to understand the physical basis of "relaxor" ferroelectricity. The behavior of relaxors is qualitatively different from conventional ferroelectric materials, in terms of the frequency-dependent response to electric fields and related properties such as the piezoelectrically driven shape changes that occur. Our investigations will explore the boundary between the relaxor phase and other parent phases. Both single crystal bulk materials and MBE-grown thin films will be investigated. We will use novel measurement techniques that simultaneously probe the behavior of relaxors with high spatial and temporal resolution. The proposed experiments will infuse much-needed empirical constraints into theory. The impact of this work will be both fundamental and practical. Relaxor behavior is prevalent in a wide class of ferroelectric materials, and is poorly understood. The cross-disciplinary nature of this research effort, involving a strong coupling of physics and material science, will enhance the experiences of students majoring in either discipline.