Microscopic observation of magnetic and electric states using optical imaging techniques

2021 Fiscal Year Final Research Report

• Project/Area Number: 18K03521
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 13030:Magnetism, superconductivity and strongly correlated systems-related
• Research Institution: Kagoshima University
• Principal Investigator: MANAKA Hirotaka 鹿児島大学, 理工学域工学系, 助教 (80359984)
• Project Period (FY): 2018-04-01 – 2022-03-31
• Keywords: 光イメージング / 複屈折 / 磁性体 / 誘電体

Outline of Final Research Achievements

Using optical imaging measurement techniques, spatial distributions of magnetic and dielectric states were observed. In antiferromagnet KNiF3, several optical domains appear when external force was applied, and their shapes change below the antiferromagnetic phase transition temperature. In quantum paraelectric SrTiO3, stress-induced ferroelectric phase transition was observed by applying external force. When external force was applied along [001], slip planes appeared along [-11-1] and [1-11]. When the temperature further decreased below 20 K, almost the uniform ferroelectric state appeared. On the other hand, when external forces were applied along [1-10], many slip planes were generated, and strain concentration also appeared around the dislocations, but the ferroelectric phase transition did not occur.

Free Research Field

物性物理学

Academic Significance and Societal Importance of the Research Achievements

一般に弾性体に対して外から力を印可すると、試料内では応力や歪みに分布が現れることが知られている。磁性体や誘電体に外から力を印可した実験も数多く報告されている。しかし試料内で発生する局所的な歪みが磁性や誘電性にどのような影響を及ぼすか、それらを観察出来る手段がこれまでなかった。本研究では光イメージング技術を用いて, 試料内の歪みや, それにともなう磁性や誘電性の変化を空間分布として定量的に評価できる方法を開発した。本技術を用いることで, 応力下での物性研究が進歩すると考えられる。