[11p-E208-1~10] 10.3 Spin devices, magnetic memories and storages

2:00 PM - 2:15 PM JST(5:00 AM - 5:15 AM UTC)Presentation by Applicant for JSAP Young Scientists Presentation AwardEnglish Presentation

[11p-E208-3] Tunnel-magnetoresistance sensor using nanocrystalline Fe-B-Cu alloy thin films as flux concentrators

〇Yichen Wang¹, Miyaura Tomoko¹, Oogane Mikihiko^1,2, Nakano Takafumi^1,3 (1.Tohoku Univ, 2.Tohoku Univ CSIS, 3.Tohoku Univ. Green X-Tech)

Keywords:

TMR sensor,soft magnetic materials,flux concentrator

This study developed TMR sensors using nanocrystalline Fe–B–Cu alloy thin-film flux concentrators to enhance magnetic-field sensitivity. The Fe–B–Cu films were prepared by RF sputtering and optimized through magnetic-field annealing. The films exhibited excellent soft magnetic properties, including a low coercivity of approximately 0.3 Oe and a high saturation magnetization of about 1250 emu/cm³. By integrating these films as flux concentrators, the sensitivity of the TMR sensors improved from 7 %/Oe to 104 %/Oe, achieving an enhancement factor of approximately 15. In the presentation, we will discuss the Cu-content dependence of the magnetic properties and the effects of different annealing processes.