Exploiting microstructure and symmetry in new ferroelectric materials

Authors
Florio, Fred
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Other Contributors
Sundararaman, Ravishankar
Meunier, Vincent
Shi, Jian
Zhang, Shengbai
Issue Date
2020-12
Keywords
Physics
Degree
PhD
Terms of Use
Attribution-NonCommercial-NoDerivs 3.0 United States
This electronic version is a licensed copy owned by Rensselaer Polytechnic Institute, Troy, NY. Copyright of original work retained by author.
Full Citation
Abstract
Ferroelectric materials exhibit naturally occurring electronic polarization states, inspiring a wide array of potential use and function in technology. Charge separation from internal fields and the bulk photovoltaic effect are promising properties for photo-current generation, and control over the orientation of ferroelectric polarization allows for non-volatile memory storage. Coupling ferroelectricity to other properties of symmetry, as in multiferroics, provides an external knob which can be used to tune such material properties as the crystal structure, band gap, and spin via the electric field; great for sensor and spintronic applications. Real-world application of ferroelectric materials is hindered however by their insulating nature; where larger band-gaps discourage photo-absorption. Semiconducting materials whichmaintain ferroelectricity are therefore highly desired. In this work I present research done on the ferroelectric materials Silver-Bismuthate (Ag2BiO3) and Cyclohexylethylamine-Triiodo-Plumbate ([CYHEA]PbI3). In addition to first principles calculations, a phase field model was developed and used to simulate larger scale effects of microstructure such as domain formation and hysteresis. [CYHEA]PbI3 is a new class of chiral-ferroelectric, akin to a multiferroic in how it couples broken symmetry in a single material. Coupling of chirality and ferroelectricity could lead to properties such as selective domain switching or optical force generation, and could find use in spintronic applications. Ag2BiO3 represents a charge-disproportionate ferroelectric, a class of materials which shows promise in photovoltaic applications. Of particular interest with this material is the presence of a Weyl semimetallic state, which is shown here to possibly be stabilized in a polar domain interface.
Description
December 2020
School of Science
Department
Dept. of Physics, Applied Physics, and Astronomy
Publisher
Rensselaer Polytechnic Institute, Troy, NY
Relationships
Rensselaer Theses and Dissertations Online Collection
Access
CC BY-NC-ND. Users may download and share copies with attribution in accordance with a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License. No commercial use or derivatives are permitted without the explicit approval of the author.