NICOP - Exploration of New Mesoscale Mechanisms for Ultrahigh Piezoelectric Responses in Relaxor Ferroelectrics
Abstract
Exploration of New Mesoscale Mechanisms for Ultrahigh Piezoelectric Responses in Relaxor Ferroelectrics:Technical:The excellent electromechanical properties of relaxor single crystals have enabled sonar transducers with exceptional capabilities (>4X power level, 50-70% reduction in size, >4X sensitivity, 2X-3X bandwidth, etc.). The mechanism responsible for the high piezoelectric response, however, has only been described qualitatively on a macro-scale. This lack of fundamental understanding has limited the material improvement effort to date to an Edisonian approach. The PI proposes to interrogate the mesoscale interaction of polar nanoregion (PNR) and long-range ferroelectric domain (LRFD). Specifically the hypothesis is that the electrostatic interaction leads to the self-poling of PNRs within LRFDs, which is partially supported by the observation of high shear piezoelectric response in relaxor-PT crystals. In this project, the PI will 1) determine the structures/phases of PNRs to validate the ~collinear structure~ model; (2) quantitatively measure and isolate the contribution of PNRs to piezoelectric and dielectric responses and analyze the results using the proposed collinear structure model; and (3) develop a phase-field model to simulate the mesoscale relaxor ferroelectric microstructures to understand the mesoscale mechanisms responsible for the ultrahigh piezoelectric responses. b. Relevance: Piezoelectric materials are the active component of sonar transducers. The research could have impact on the following Naval S&T Focus Areas: platform design & survivability, power and energy, and power projection & integrated defense. c. Coordination: Dr. Wallace Smith and Dr. Harold Robinson of ONR 332; the project is also relevant to the intended TTCP dislogue on functional materials (in discussion). d. Desired Outcome: The findings will add to the fundamental knowledge of the electromechanical behavior of polar nanoregions and how PNRs contribute to the structure-property relationships in relaxor-PY crystals. In addition, the understanding of the mesoscale mechanisms responsible for the ultrahigh piezoelectric response is critical to the development of the next generation transducer materials, allowing materials-by-design based on specific application requirements.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Sep 30, 2016
- Source ID
- N629091612126
Entities
People
- Shujun Zhang
Organizations
- Office of Naval Research
- United States Navy
- University of Wollongong