Collaborative Research: FRG: Local Dynamic Origins of Relaxor Ferroelectricity

我们的重点研究小组成员来自匹兹堡大学和宾夕法尼亚州立大学将试图了解"弛豫"铁电性的物理基础。 我们的研究将探索弛豫相和其他母相之间的边界。 单晶体材料和分子束外延生长的薄膜将被调查。 我们将使用新的测量技术，同时探测弛豫子的空间和时间行为。 拟议中的实验将为理论注入急需的经验约束。 这项工作的影响将是根本性的和实际的。 弛豫行为在广泛的铁电材料中普遍存在，并且知之甚少。 同时，弛豫单晶可以表现出1%的大的非滞后应变，90%的机电耦合和出色的介电和极化值，性能远远超过大多数适当的铁电体。 这项研究工作的跨学科性质，涉及物理学和材料科学的强耦合，将提高学生在任何一个学科的经验。 我们的重点研究小组将试图了解“弛豫”铁电性的物理基础。 弛豫体的行为在对电场的频率依赖性响应和相关性质（例如发生的压电驱动形状变化）方面与常规铁电材料有质的不同。 我们的研究将探索弛豫相和其他母相之间的边界。 单晶体材料和分子束外延生长的薄膜将被调查。 我们将使用新的测量技术，同时探测高空间和时间分辨率的弛豫行为。 拟议中的实验将为理论注入急需的经验约束。 这项工作的影响将是根本性的和实际的。 弛豫行为在广泛的铁电材料中普遍存在，并且知之甚少。 这项研究工作的跨学科性质，涉及物理学和材料科学的强耦合，将提高学生在任何一个学科的经验。

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.