Creation and Mechanical-Structural Control of Topological Ferroelectrics by Porous Metamaterials

2022 Fiscal Year Final Research Report

• Project/Area Number: 21K18673
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 18:Mechanics of materials, production engineering, design engineering, and related fields
• Research Institution: Kyoto University
• Principal Investigator: Shimada Takahiro 京都大学, 工学研究科, 教授 (20534259)
• Project Period (FY): 2021-07-09 – 2023-03-31
• Keywords: 多孔質メタマテリアル / 複合物理特性 / ナノ強誘電体 / Phase-Field法 / 第一原理計算

Outline of Final Research Achievements

In this study, I focus on ferroelectric porous metamaterials and evaluate their microscopic ferroelectric polarization and external field response by first-principles calculations and phase-field method. We found that novel topological polarizations such as multiple vortices and spirals, which are completely different from linear polarizations in homogeneous materials, appear in the nanoporous metamaterials. We also found that the hysteresis response to electric field strongly depends on the microscopic structure of the nanoporous metamaterials, and showed that it can be designed by the microstructure of the nanoporous metamaterials. Furthermore, we have also evaluated porous metamaterials of magnetic materials and composite metamaterials of ferroelectrics and magnetic materials, and found that their functions strongly depend on their microstructures.

Free Research Field

計算材料力学

Academic Significance and Societal Importance of the Research Achievements

本研究は、多孔質メタマテリアルの微視的内部構造とひずみ分布によって位相幾何学的な強誘電性を創り出すことで、材料力学的観点に基づく全く新しい機能創成の可能性を開拓する点に学術的意義がある。特に、メタマテリアルは光学・音響分野にて主たる研究対象となっているが、本研究では電気-力学的機能を主とするトポロジカル強誘電性のメタマテリアルなる新たな概念を立ち上げる点に特徴がある。本成果により、均質材では達成し得なかったヒステリシス応答や巨大な圧電効果などの新規機能を付与することができ、ナノ機械デバイスや情報デバイスの超大容量化といった産業応用への寄与の観点で社会的意義がある。