Integrated Multi-Scale Modeling of Complex Compositions in Textured Ceramic Structures
Abstract
Approved for Public ReleaseThis project proposes theoretical investigations into the structure, composition, and physical mechanisms of textured piezoelectric ceramics, in order to provide guidance toward design of materials with superior SONAR detection and broadcast properties. Piezoelectric materials couple mechanical and electrical energy, making them key components for a broad range of electromechanical applications. The increasing demand for high performance piezoelectric devices requires improvement in the piezoelectricity, where one important approach is to exploit piezoelectric anisotropy. By aligning the polarization direction with the preferred crystallographic direction in a single crystal, the piezoelectricity could be significantly increased. However, growing single crystal piezoelectrics is still an outstanding challenge. To sidestep this challenge, growing textured piezoelectric ceramics through templated grain growth is considered an alternative approach that balancesthe performance and fabrication difficulties. Textured piezoelectric ceramics are complicated systems containing multiple components (e.g., grains, domains, and phases) and the interfaces separating them (e.g., grain boundaries, domain walls, and phase boundaries). Moreover, each of these components and interfaces are multi-compositional and may exchange elements between them, which further increases the complexity. The coexistence of these components and the interaction between them could significantly impact the piezoelectric performance. However, due to theoretical complexity and the limitations of simulation techniques, the understanding of these interactions and how they would affect piezoelectric performance is still very limited. Here, to tackle these important challenges, we propose the following research directions: 1. Development of new simulation methods for complicated textured piezoelectric ceramic systems. These will provide powerful tools, including multi-compositional bond-valence molecular dynamics and machine learning force fields, and the ab initio Grand Canonical Monte Carlo method, for the investigation of textured piezoelectric ceramics. 2. Investigation of the compositional variation of the textured piezoelectric ceramics. We aim to employ our newly developed simulation methods to figure out the structural and compositional variations of the complicated interfaces that exist throughout piezoelectric ceramics, such as grain boundaries and template-matrix interfaces. 3. Investigation on the impact of structural misalignment in textured piezoelectric ceramics. Based on previous results, we aimto investigate how the in-plane misalignment and the defects (such as grain boundaries) could impose mechanical confinement to the piezoelectric grains and thus impact the overall piezoelectric performance. The investigations proposed are designed to: 1. Provide critical structural and compositional information of various components and interfaces in textured piezoelectric systems, which is along-standing obstacle to further understanding in these materials. 2. Understand how the mechanical confinement imposed by interfaces (e.g., grain boundaries) on the piezoelectric grain could affect the piezoelectricity and thus how one could engineer these interfaces to optimize the textured piezoelectric ceramics performance. The development of simulation methods would also provide powerful tools to the community for various piezoelectric research projects. Taken together, these investigations would provide key information and insights for improving the response of SONAR piezoelectrics.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Nov 08, 2024
- Source ID
- N000142412500
Entities
People
- Andrew M Rappe
Organizations
- Office of Naval Research
- United States Navy
- University of Pennsylvania