control of site occupancy of cations and magnetic properties by epitaxial strain

2022 Fiscal Year Final Research Report

• Project/Area Number: 21K14413
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 26020:Inorganic materials and properties-related
• Research Institution: 防衛大学校(総合教育学群、人文社会科学群、応用科学群、電気情報学群及びシステム工学群)
• Principal Investigator: Hamasaki Yosuke 防衛大学校(総合教育学群、人文社会科学群、応用科学群、電気情報学群及びシステム工学群), 応用科学群, 助教 (40826624)
• Project Period (FY): 2021-04-01 – 2023-03-31
• Keywords: 強誘電体 / 磁性体 / 薄膜

Outline of Final Research Achievements

We focused on ε-Fe2O3, a promising candidate for room-temperature multiferroic materials. However,ε-Fe2O3 has a large leakage current due to valence fluctuation, making it difficult to measure its ferroelectricity. This leakage current can be suppressed by replacing iron with trivalent nonmagnetic elements, but the replacement with nonmagnetic elements makes the magnetic phase transition temperature lower. We focused on the fact that the magnetic interaction in ε-Fe2O3 varies greatly depending on the occupied sites of magnetic elements, and confirmed the improvement of magnetic properties by changing the site occupancy of magnetic elements in the thin film by epitaxial strain.

Free Research Field

材料科学

Academic Significance and Societal Importance of the Research Achievements

本研究は鉄酸化物強誘電体に対し、リーク電流抑制目的に置換した非磁性元素のサイト占有率を基板からの格子歪により制御したものである。この結果は、室温で磁気秩序と強誘電性の両物性を発現させる一つの設計方法を提案することができたと考える。