Presentation Information
[23p-1BJ-4]Design for high sensitivity in magnetic vortex type linear TMR sensors
〇(M1)Seiya Takano1, Muftah Al-Mahdawi2, Mikihiko Oogane1,3 (1.Graduate School of Engineering, Tohoku Univ., 2.Libya International Medical Univ., 3.CSIS, Tohoku Univ.)
Keywords:
TMR sensor,magnetic vortex
The Tunnel Magneto-Resistance (TMR) sensor is a magnetic sensor which operates at room temperature. This study aims to enhance the sensitivity of a magnetic vortex-type linear TMR sensor by adjusting various magnetic parameters through thermal treatment in a magnetic field. Previous results showed that in discs of Ni80Fe20 (Py) alloy, the magnetic vortex structure, typically a few micrometers in diameter, expanded to 30-40μm after applying thermal treatment with around 1500 erg/cc magnetic anisotropy. As the vortex size and initial permeability are proportional, this discovery holds the potential for enhancing the sensitivity of magnetic vortex-type linear TMR sensors. However, the reason for the expansion of the magnetic vortex remains unclear. Therefore, this experiment aims to simulate and investigate the causes of this vortex expansion and its impact on sensor sensitivity. Micro-magnetic simulation using MuMax3 was employed to verify the magnetic vortex expansion. Results showed that the introduction of bulk DMI results in larger-than-usual magnetic vortex structures. Controlling bulk DMI and leveraging larger magnetic vortex-free layers could potentially enhance the sensitivity of magnetic vortex-type linear TMR sensors.