Film structure evolution and magnetic property improvement of Pd alloy film by hydrogen

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K14137
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 30010:Crystal engineering-related
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: Harumoto Takashi 東京工業大学, 物質理工学院, 助教 (80632611)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: 水素吸蔵合金 / 磁性薄膜 / パラジウム / 磁歪 / 磁気異方性 / 応力 / 欠陥 / 磁気弾性効果

Outline of Final Research Achievements

This study focused on the hydrogen-induced film structure evolution and magnetic property enhancement in palladium (Pd)-based alloy films. The experimental and theoretical results revealed that the hydrogenation properties of the films are sensitive to the stress and defects in the films. Also, the crystallinity of the films can be improved by hydrogen absorption and subsequent desorption. Furthermore, magnetic properties, such as magnetic anisotropy and magnetostriction, of the films can be controlled by hydrogen. The detailed study revealed that the hydrogen affects the orbital magnetic moment of magnetized Pd, which is the origin of large magnetostriction in these alloys.

Free Research Field

薄膜工学

Academic Significance and Societal Importance of the Research Achievements

水素脆化に代表されるよう、水素は、従来、金属に対しては「有害」な元素であるとされてきた。しかし、薄膜状態の金属に対しては、必ずしも有害ではなく、寧ろ、膜中の欠陥量や応力、更には、磁気特性をも制御でき得る「有用」な元素であると判明した。水素は、軌道磁気モーメントに関連する磁気特性、即ち、磁気異方性や磁歪などに対して大きな影響力を有していた。これら知見は、水素社会の実現、並びに、金属薄膜の高性能/高機能化に役立つものである。