Ferroelectric and magnetic double-helices in low-dimensional nanostructures and their mechanical coupling

2016 Fiscal Year Final Research Report

• Project/Area Number: 26289006
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• 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): 2014-04-01 – 2017-03-31
• Keywords: ナノ構造 / 強誘電体 / 磁性 / マルチフィジックス特性 / 第一原理解析 / マルチフェロイクス / ナノワイヤ / 薄膜

Outline of Final Research Achievements

In this study, novel ferroelectric and ferromagnetic ordering emerged in low-dimensional nanoscale multiferroics is analyzed using first-principles calculations based on quantum-mechanics theory. In nanowires, for exmaples, both ferroelectric polarization and magnetic moment form a spiral way, i.e., double-helix structures. This is due to both depolarizing field due to surface charges and unique bonding formed in nanostructures. In addition, such helical ferroelectric and magnetic polarizations can be switched by mechanical torsion, suggesting that there exists unique coupling among mechanical, ferroelectric, and magnetic properties, i.e., multi-physics properties in nanostructures.

Free Research Field

工学