Investigation of large magnetization and polarization in Bi(Fe,Co)O3 epitaxial thin films

2014 Fiscal Year Final Research Report

• Project/Area Number: 25600067
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Applied materials
• Research Institution: Tohoku University
• Principal Investigator: NAGANUMA Hiroshi 東北大学, 工学(系)研究科(研究院), 助教 (60434023)
• Project Period (FY): 2013-04-01 – 2015-03-31
• Keywords: BiFeO3 / マルチフェロイクス / BiCoO3 / 極薄膜

Outline of Final Research Achievements

BiFeO3 and BiCoO3 have a large polarization, and their solid solution of Bi (Fe, Co) O3 has a high spontaneous polarization/magnetization. Bi Fe(Co) O3 could maintain unsymmetrical crystal structure even if a film became ultrathin owing to epitaxial strain from single crystal SrTiO3 substrates. As a result of element specific XMCD measurements, was suggested that increasing the interfacial magnetization induced between BiFeO3 and CoFe. This may consider that electric charge formed at the interface by the large spontaneous polarization in the BiFeO3 which changing the angle of Fe of BiFeO3 and/or modulates the band structure of CoFe. This result suggested that we can expect the observation of the large tunnel electrical- and magneto-resistance effect using the Bi (Fe, Co) O3 a barrier material.

Free Research Field

総合理工