Elucidation of Formation and Extinction Mechanisms of Topological Domain Structures in Hexagonal Manganese Oxides

2022 Fiscal Year Final Research Report

• Project/Area Number: 20H02441
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 26020:Inorganic materials and properties-related
• Research Institution: Kyushu Institute of Technology
• Principal Investigator: Horibe Yoichi 九州工業大学, 大学院工学研究院, 教授 (80360048)
• Co-Investigator(Kenkyū-buntansha): 佐藤 幸生 九州大学, 工学研究院, 准教授 (80581991)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 電子顕微鏡 / マルチフェロイック / ドメイン / 局所構造

Outline of Final Research Achievements

First, we focused on the initial composition of the raw material rods and studied the stability of single crystal growth as the Mn concentration changes in YMnO3. As a result, we found that stable single-crystal growth was possible with the Mn-deficient composition, although a small amount of Y precipitates appeared on the surface and cross section of the single crystal. From these results, it is clear that single-crystal growth can be stabilized by controlling the amount of Mn deficiency. Next, using the obtained single crystals, we observed the domain structure change of the cloverleaf domain structure in this system when an external electric field was applied, using transmission electron microscopy. As a result, it was found that the domain width decreases linearly with the application of a large electric field. Theoretical calculations of the domain structures of the obtained results were also attempted.

Free Research Field

材料物性学

Academic Significance and Societal Importance of the Research Achievements

酸化物強誘電体は、電気回路等に必要不可欠な応用上重要な材料であり、様々な材料特性の向上や新奇物質の探索など様々な研究が行われている。本系における大型で良質な単結晶育成条件の確立は、社会的にも意義が大きいと考えられる。また本系におけるドメイン構造は、一般的な強誘電ドメインとは異なるユニークな挙動を示すことが知られており、ドメイン形態や界面物性など注目を集めている。本研究の結果はこれらの特性の理解に貢献すると期待される。