PZT thin film with perfectly in-plane polarization orientation for 5G high-speed communication technology

2021 Fiscal Year Final Research Report

• Project/Area Number: 20K15372
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 36010:Inorganic compounds and inorganic materials chemistry-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: Ehara Yoshitaka 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), 電気情報学群, 講師 (00868755)
• Project Period (FY): 2020-04-01 – 2022-03-31
• Keywords: 強誘電体 / 強弾性ドメイン / 圧電体 / エピタキシャル膜

Outline of Final Research Achievements

(1) Preparation of a ferroelectric film with perfectly in-plane polarization orientation and film thickness dependence of its structure were carried out. As a result, it was confirmed that a ferroelastic domain was generated when the critical film thickness was about 90 nm. (2) To investigate the relationship between the ferroelastic domain switching amount and the crystal structure, various Zr amounts were dissolved in the film to form a thin film. As Zr increased, the film thickness region where the ferroelastic domain was introduced expanded. (3) The ferroelastic domain switching speed was investigated using synchrotron radiation X-ray diffraction (SPring-8). As a result of observing a voltage of several hundred nanoseconds, it was confirmed that the square structure with a small Zr ratio has a superior response speed in the high-frequency region (several MHz or more).

Free Research Field

圧電体薄膜

Academic Significance and Societal Importance of the Research Achievements

高周波における強弾性ドメインの応答性に関する成果は、非鉛材料にも展開できる可能性がある。実際に非鉛圧電材料でもドメイン回転の寄与がPZTと同様にユニバーサルな振る舞いを示すことも確認できており、アクチュエータデバイスの材料技術を維新する存在となる。
これにより電子機器による環境汚染の低減と持続可能な技術として社会的問題解決に貢献ができると期待している。