Creation and mechanical control of non-trivial topological polarizations in porous nanostructures

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K21918
• 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, 准教授 (20534259)
• Project Period (FY): 2019-06-28 – 2021-03-31
• Keywords: ナノ多孔質材 / 強誘電体 / マルチフィジックス特性 / Phase-Field法 / 第一原理解析

Outline of Final Research Achievements

In this study, we analyzed and investigated the topological polarization order developed inside SriO3　nanoporous materials. The ferroelectric domain around the nanopores is induced by mechanical loading, and these domains expands and connects with the increase of external load. Furthermore, the polarization order in the domain strongly depends on the arrangement of the nanopores, and various orders such as multiple vortex structures, vortex network structures, and helical structures can be formed. In the nanocomposite material, a dense and fine ferroelectric domain structure appears depending on the volume fraction of the two phases, and the piezoelectric effect is several times higher than that of the homogeneous counterpart. The function can be designed by the microscopic nanopore structure.

Free Research Field

計算材料力学

Academic Significance and Societal Importance of the Research Achievements

強誘電（圧電）材料は、微小電気機械や生体デバイス、情報機器などに用いられる。本成果は、材料内の微視的構造によって、主たる機能である分極パターンや圧電応答特性などを設計・向上できることを示したものであり、これらのデバイスの機能設計・構造設計の指針を示すものである。特に、本材料の特色は、電気エネルギーと機械エネルギーを相互変換できる点にあり、この相互変換の高効率化を成す基本原理を示した点に学術的意義がある。