NICOP - Exploration and design of high performance relaxor ferroelectrics based on microstructure study
Abstract
ProblemDespite the extensive studies and commercialization of relaxor-PT crystals in medicalimaging, there is still no clear understanding of the physical origin of the ultrahighelectromechanical properties. The lack of understanding of the extraordinarily largeelectromechanical responses of relaxor ferroelectric solid solution systems has been the mainobstacle to the development of next-generation high-performance piezoelectrics. We proposeto study advanced piezoelectric materials based on local structure heterogeneity concept, forapplication in high performance transducers with better electrical impedance matching andminiaturization, further a vision to advance underwater acoustic applications with broaderdesign freedom. This will offer a paradigm of designing new materials with enhancedfunctionalities.ObjectivesThe main objective of the proposed research effort is to understand the following questions:- What???s the relationship of the local microstructure and local chemistry in relaxorferroelectric systems? Understanding this question can help to control the localstructure heterogeneity by material design.- What???s the role of A-site cation and B-site cation (including the single or complexcations) on piezoelectric properties in relaxor ferroelectric systems. Understandingthis question will help design and exploration of new piezoelectric materials.- What???s the interaction of the local structure heterogeneity and surrounding matrixphase/structure, i.e., the relationship between NHPR (nanoscale heterogeneous polarregions) and LRFD (long range ferroelectric domain structure)? Understanding thisquestion may clarify why some relaxor systems only exhibit dielectric relaxation withmedium or even zero piezoelectric properties, while other systems show greatlyenhanced piezoelectric performance.Technical approachesExperiments will be designed on property characterization (ferroelectric and dielectricmeasurements over a broad temperature range) and microstructure observation (TEM, PFM,Synchrotron diffraction and Neutron scattering), and theoretical calculation/simulation onmesoscale (Phase field modeling) and atomic scale (first principle calculation and moleculardynamic simulation). Based on the fundamental understanding, we will design relaxorferroelectric materials with high piezoelectric properties, through ceramic fabrication andcrystal growth.OutcomesThis project will establish the fundamental understanding of the relationships of materials???chemical composition, microstructure, structure, property and potential device performance,guiding the material design through local structure hetereogeneity. All the experiments,modeling/simulation, technical studies will be presented to various conferences, includingInternational Workshop on Acoustic Transduction Materials and Devices, IEEE InternationalSymposium on Applications of Ferroelectrics to discuss the research progress and potentialinternational collaborations in addition to the existing collaborations with PSU and NCSU inUS; and published in scientific literature/peer reviewed journals.Impact on DoD capabilitiesThis project will impact the DoD capabilities by providing knowledge and technology of highperformance piezoelectric materials, including the microstructure tuning, property tailoringand material design, enabling advanced ultrasound transducers for medical imaging andunderwater acoustic applications, which will offer enhanced sensitivity and broadened devicedesign freedom.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Sep 19, 2018
- Source ID
- N629091812168
Entities
People
- Shujun Zhang
Organizations
- Office of Naval Research
- United States Navy
- University of Wollongong