Inhomogeneity in perovskite-type ferroelectrics probed by angle-resolved polarized Raman spectroscopy

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K04931
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Applied materials
• Research Institution: Shimane University
• Principal Investigator: TSUKADA Shinya 島根大学, 学術研究院教育学系, 准教授 (90570531)
• Co-Investigator(Kenkyū-buntansha): 秋重 幸邦 島根大学, 学内共同利用施設等, 理事 (30150981) ; 藤井 康裕 立命館大学, 理工学部, 助教 (50432050)
• Research Collaborator: OHWADA Kenji
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 強誘電体 / リラクサー / ブリルアン分光 / ラマン分光 / 放射光回折 / 強誘電性相転移 / 不均一構造

Outline of Final Research Achievements

Inhomogeneity in perovskite-type ferroelectrics, a key to make ferroelectrics more convenient, was investigated in a broad spatial and time scales. Static properties were probed by an electron microscope and synchrotron X-ray diffraction, while dynamic properties were by Brillouin and Raman spectroscopy. The results clearly show roles of inhomogeneity on macroscopic properties such as dielectric constant and piezoelectric constant. We found that nanometer-scale fractal structures fluctuating in picoseconds are important to enhance ferroelectric properties.
In addition, relaxors were investigated by angle-resolved polarized Raman spectroscopy, showing that dynamic and static aspects of the inhomogeneity.

Free Research Field

物性物理学

Academic Significance and Societal Importance of the Research Achievements

高誘電率・高圧電定数を有するリラクサーは，性能が高く便利な反面，環境に有害な鉛を含むなど課題がある．リラクサーの相転移や構造を広い時空間で解明することは，より安全で高度な強誘電体の開発に結びつくはずである．