Unusual Emergence of Magnetism in Ferroelectric Nanostructures and Proposal of Multi-Functional Design Concepts

2014 Fiscal Year Final Research Report

• Project/Area Number: 25630010
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Materials/Mechanics of materials
• Research Institution: Kyoto University
• Principal Investigator: SHIMADA TAKAHIRO 京都大学, 工学(系)研究科(研究院), 助教 (20534259)
• Project Period (FY): 2013-04-01 – 2015-03-31
• Keywords: ナノ構造 / 強誘電体 / 特異的磁性発現 / マルチフィジックス特性 / 第一原理解析

Outline of Final Research Achievements

In this study, the emergence and properties of magnetism in nanostructured and nano-defected ferroelectrics are investigated by the first-principles calculations using parallel computations. It is revealed that oxygen vacancies coupled with grain boundaries and free surfaces that characterize the nano-ferroelectrics induce magnetism. This emergence of magnetism is due to the split of the electronic state of oxygen vacancies, i.e., defect state. The emerged magnetism at the oxygen vacancies are strongly coupled with ferroelectric polarizations, i.e., the existence of magnetoelectric coupling. In addition, the magnetism also interacts with applied strains, leading to a various magnetic phase transitions including ferromagnetic, antiferromagnetic, and nonmagnetic phases. This clearly indicates that there exists a remarkable multi-physics property.

Free Research Field

工学