Microscopic mechanism of electromagnetic excitations in multiferroics

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K05154
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Condensed matter physics II
• Research Institution: High Energy Accelerator Research Organization
• Principal Investigator: Sagayama Hajime 大学共同利用機関法人高エネルギー加速器研究機構, 物質構造科学研究所, 准教授 (90436171)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 電気磁気効果 / 交差相関 / スピン格子相互作用 / スピン軌道相互作用

Outline of Final Research Achievements

The object of this project is clarifying microscopic mechanism of the cross-correlation properties and understanding dinamical magnetoelectric phenomena in multiferroic materials. First, in order to understand the electromagnetic excitations observed around E ~ 2.5meV in representative spin-spiral multiferroic material TbMnO3, we have performed inelastic neutron scattering experiments. We found prabolic magnetic excitations around (1 -1 0) which is one of the crystallcraphic gamma point, although theoretical studies previously predicted that non-dispersive excitations in the L = 0 plane. Energy gap at the gamma is estimated to be 2.5 meV, which is close to that of the electromagnetic excitaions.
To obtaine fine-understanding of the electromagnetic interaction in multiferroic materials, we have performed circulay polarized x-ray diffraction experiment on single crystal sample of YFeO3. We have suceeded In observing direct coupling of the antiferroelectricity and ferromagnetisity.

Free Research Field

強相関、磁性