Fabrication of brain-inspired devices by control of Fe valence state in iron oxides

2021 Fiscal Year Final Research Report

• Project/Area Number: 18K18850
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 21:Electrical and electronic engineering and related fields
• Research Institution: The University of Tokyo
• Principal Investigator: Munetoshi Seki 東京大学, 大学院工学系研究科(工学部), 准教授 (40432439)
• Project Period (FY): 2018-06-29 – 2022-03-31
• Keywords: 酸化鉄 / スピングラス

Outline of Final Research Achievements

New cluster-glass materials were fabricated, and their physical properties were investigated towards the creation of room-temperature brain-mimic devices. Especially, cluster-glass thin films with high glass-transition temperature and high responsivity to light irradiation were successfully fabricated using iron oxides with a spinel-type crystal structure as host materials. It was found that the carrier type of these films can be controlled by modulating the valence state of cations in the films. Furthermore, the propagation of spin-wave was successfully observed in the cluster-glass Al-substituted γ-Fe2O3 thin films. This result can be utilized in the development of the devices with ultra-low energy consumption.

Free Research Field

機能材料科学

Academic Significance and Societal Importance of the Research Achievements

本研究では、高温クラスターグラスを発現する物質を作製し、その磁気特性の光制御を実現しただけでなく、グラス状態を室温においてスピン波伝搬の形で簡易かつ高感度で検出することに成功した。この成果は、莫大な消費電力のもと決定論的作動を高速で行う従来のノイマン型コンピュータに代わる、柔軟かつ超低消費電力型の革新的情報処理システムの実現への道を開くものであると考えられる。また、本研究で扱った材料・素子を構成する元素の多くが、Fe(クラーク数4位）、O（1位）、Si(2位）、Mg（8位）等の地球上に豊富に存在する資源であることは、産業応用の観点から大きな意義を持っている。