Understanding and Designing Complex Ferroelectrics from First Principles
Abstract
Understanding and Designing Complex Ferroelectrics from First PrinciplesAbstract:The objective of this proposal is to build a wo"rld-class research program at the University of Arkansas (UA), aimed at (1) understanding relaxor ferroelectrics at a microscopic le""vel, including their enhanced electrocaloric conversion; (2) design novel ferroelectric materials with large physical responses and/""or original properties; and (3) simulate and reveal complexlight-matter phenomena in functional ferroelectrics, such as electro-opt""ic and photo-elastic effects. This research program is highly relevant to national defense, since U.S. NAVY sonar-listening devices"" are made of ferroelectrics and since it can lead to the development of new generation of, e.g., cooling and communication devices."This objective will be achieved thanks to the development and use of the following state-of-the-art ab-initio numerical tools: (i)" the accurate first-principles techniques, including total energy calculations, computation of phonon spectrum, modern theory of po"larization and treatment of electric-field effects; and (ii) effective Hamiltonian approaches that extendthe reach of first-principles calculations by realistically mimicking finite-temperature static and dynamical properties of complex ferroelectrics. Collaborations with well-known inter-national research groups having a vital experimental program on ferroelectrics will also bestrengthene"d, to ground our simulations and fully understand the systems to be studied.Various effects in many compounds are going to be inve""stigated. Example includes the identification of the origin(s) of the dielectric relaxation, phonon localization and large electroca""loric response in Pb(Mg1=3Nb2=3)O3 and Pb(Mg,Nb,Ti)O3 relaxor ferroelectrics.Another example is the design of novel ferroelectric m""aterials via defect-engineering in (La,Ba)Co2O5, and the Brownmillerite Sr2Co2O5 and Ca2(Fe,Al)O5 compounds. Other investigations wi"ll be conducted to optimize the change of refractive index under electric eld and the change of shape of materials under light in P"bTiO3, Pb(Zr,Ti)O3, BaTiO3 and BiFeO3 lms. The e -ect of formation of polarization and domains on structural, optical and electrica" properties of hybrid perovskites will also be addressed. An unprecedented microscopic knowledge of ferroelectrics will be gained" and discovery of ""wunderbar"" materials will occur, thanks to the diversity of the techniques, the variety of systems to be investig""ated, and the collaborations between UA and other institutions specialized in ferroelectrics. These joint e -orts will be the basis"f a network for futurecollaborations. The granting of this proposal is also critical to continue to generate high-quality publicati"ons from, and bring international attention to, UA.Moreover, this proposal will not only tackle and understand real material issue""s (such asmicroscopic features of relaxor ferroelectrics), but will also constitute one e -ective approach for the materials genome"" initiative (by, e.g., using the novel provocative idea of defect-engineering). This proposal should therefore help in reducing the" cost of experimental growth when searching for optimized materials.The research program will be integrated into the educational experience of UA graduate students. This experience is expected to be of substantial benefits to them both for knowledge-learning pur"poses, and for enhancing students ability to compete on the jobmarket { via the development of computer skills and visits to other" institutions.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Sep 29, 2017
- Source ID
- N000141712818
Entities
People
- Laurent Bellaiche
Organizations
- Office of Naval Research
- United States Navy
- University of Arkansas System