Development of New Energy Harvesting Thin Film Materials Utilizing Effect of Magnetic Easy Axis Switching

2017 Fiscal Year Final Research Report

• Project/Area Number: 16K14372
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Physical properties of metals/Metal-base materials
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: SHI JI 東京工業大学, 物質理工学院, 教授 (70293123)
• Co-Investigator(Kenkyū-buntansha): 春本 高志 東京工業大学, 物質理工学院, 助教 (80632611)
• Project Period (FY): 2016-04-01 – 2018-03-31
• Keywords: 磁気異方性 / 磁気弾性効果 / エネルギー変換 / 応力・歪み測定

Outline of Final Research Achievements

In this work, we try to establish a new energy harvesting technique by utilizing the effect that the magnetization easy axis of CoPt/AlN multilayers can be change from in-plane direction to perpendicular direction by changing the sign of elastic strain inside the CoPt layers. We tried several methods to introduce elastic strain externally to the CoPt layers, which include deposition of an extra Pd layer, hydrogen absorbing of the Pd layer, or using flexible substrate materials that can be bent mechanically. The results have shown that by introducing strain to the CoPt/AlN multilayer, we definitely can switch the magnetic easy axis from perpendicular direction to in-plane direction. This opens the possibility of using such material as an energy harvesting material that transfers vibration energy into electricity.

Free Research Field

Metal physics, Magnetic thin films