【公開日：2023.07.31】【最終更新日：2023.05.12】
課題データ / Project Data
課題番号 / Project Issue Number
22UT0226
利用課題名 / Title
Study on Memristor using Perovskite-Spinel PbTiO3-CoFe2O4 Vertically Aligned Nanocomposite Thin Films
利用した実施機関 / Support Institute
東京大学
機関外・機関内の利用 / External or Internal Use
内部利用（ARIM事業参画者以外）/Internal Use (by non ARIM members)
技術領域 / Technology Area
【横断技術領域 / Cross-Technology Area】（主 / Main）計測・分析/Advanced Characterization（副 / Sub）-
【重要技術領域 / Important Technology Area】（主 / Main）高度なデバイス機能の発現を可能とするマテリアル/Materials allowing high-level device functions to be performed（副 / Sub）量子・電子制御により革新的な機能を発現するマテリアル/Materials using quantum and electronic control to perform innovative functions
キーワード / Keywords
X線回折/X-ray diffraction,ナノエレクトロニクスデバイス/ Nanoelectronics device,スピントロニクス/ Spintronics
利用者と利用形態 / User and Support Type
利用者名（課題申請者）/ User Name (Project Applicant)
李 海寧
所属名 / Affiliation
東京大学
共同利用者氏名 / Names of Collaborators in Other Institutes Than Hub and Spoke Institutes
関 宗俊,Wang Xinjue
ARIM実施機関支援担当者 / Names of Collaborators in The Hub and Spoke Institutes
利用形態 / Support Type
（主 / Main）機器利用/Equipment Utilization（副 / Sub）-
利用した主な設備 / Equipment Used in This Project
UT-202：高輝度In-plane型X線回折装置
UT-305：環境制御マニュアルプローバステーション
報告書データ / Report
概要（目的・用途・実施内容）/ Abstract (Aim, Use Applications and Contents)
We applied the XRD equipment (SmartLab 9 kW) in the University of Tokyo to measure the thickness of fabricated thin film. In the meantime, we utilized the FCE1EEA-200 device of the environmental control manual probe station for the ferroelectricity measurement in the University of Tokyo.
実験 / Experimental
The top electrode Pt/Cr or Au/Cr was deposited by sputtering equipment on the top of the PbTiO3 thin film, and such Au/Cr/PbTiO3/SrRuO3/SrTiO3 capacitor structure is shown in Fig. 1(a). In the meanwhile, PbTiO3 is also fabricated on another substrate Pt/HfO2/Si, and the top electrode Pt/Cr was also deposited by sputtering on the top of the PbTiO3 thin film, as shown in Fig. 1(b). The room-temperature ferroelectric properties of these two kinds of capacitor structures were evaluated by the FCE1EEA-200 equipment by changing the frequency and the amplitude of input voltages.
結果と考察 / Results and Discussion
(1) The thickness of our sample was successfully measured by the XRD SmartLab (9 kW). (2) The ferroelectric properties of PbTiO3 thin film of these two capacitor structures were measured and confirmed at room temperature. Frequency-dependent and maximum voltage-dependent polarization hysteresis loops were clearly obtained. As illustrated, the capacitor structure (a) exhibited poor quality room-temperature ferroelectric loops, which indicated a large leakage current over the ferroelectric switching. This was possibly due to the vacancies of Pb or O atoms during the fabrication. The polarization saturation was close to 40 μC/cm2, which is lower than the reported value of about 60 μC/cm2. On the other hand, the capacitor structure (b) showed improved room-temperature ferroelectric loops and large values of polarization saturation. It should be also noted that when the input voltage was low, it was not enough to switch the domain walls and the polarization hysteresis loops were not obvious. Such a comparison shows that the PbTiO3 thin film deposited on Pt/HfO2/Si has a better quality and less vacancies.
図・表・数式 / Figures, Tables and Equations
Fig. 1 (a) Au/Cr/PbTiO3/SrRuO3/SrTiO3 and (b) Pt/Cr/PbTiO3/SrRuO3/Pt/HfO2/Si capacitor structure and their polarization-voltage hysteresis loops measured at room temperature.
その他・特記事項（参考文献・謝辞等） / Remarks(References and Acknowledgements)
Thanks to the administrator Mr. Fukawa for helping us use the XRD equipment (SmartLab 9 kW).
成果発表・成果利用 / Publication and Patents
論文・プロシーディング（DOIのあるもの） / DOI (Publication and Proceedings)
口頭発表、ポスター発表および、その他の論文 / Oral Presentations etc.
- 〇Haining Li（東京大学）, Hiroyasu Yamahara, Hitoshi Tabata, Munetoshi Seki、Effects of Rare-earth Eu3+ Distribution on Magnetic and Electrical Properties of Spinel Fe3O4 Thin Films、9th International Symposium on Control of Semiconductor Interfaces (ISCSI-IX)、2022/9/5
- 〇Xinjue Wang（東京大学）, Haining Li, Hiroyasu Yamahara, Hitoshi Tabata, Munetoshi Seki、Multiferroic ε-Fe2O3 Thin Films for Highly Efficient Visible Light Photoelectrochemical Water Splitting、2023年第70回応用物理学会 春季学術講演会、2023/3/17
特許 / Patents
特許出願件数 / Number of Patent Applications：0件
特許登録件数 / Number of Registered Patents：0件