Enhancing Efficiency of 2D Materials-Based Spintronics Devices by Achieving Ultra-Low Coercivity

Ting-Chun Huang^1,2*, Chiashain Chuang³, Ya-Ping Hsieh², Mario Hofmann¹

¹Physics, National Taiwan University, Taipei, Taiwan
²Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan
³Electronic Engineering, Chung Yuan Christian University, Taoyuan, Taiwan

* Presenter:Ting-Chun Huang, email:timothy1207s@gmail.com

The incorporation of two-dimensional (2D) materials into spintronic devices offers promising avenues to overcome the challenges posed by high coercivity in conventional magnetic tunnel junctions (MTJs), where interfacial issues and oxide spacers limit performance. While 2D materials theoretically offer advantages such as reduced interdiffusion and weak spin-orbit coupling, their experimental implementation has yet to yield significant reductions in coercivity. In this work, we present a significant advancement in coercivity reduction for MTJs by utilizing an Uninterrupted Contact Deposition (UCD) technique to fabricate ultra-clean interfaces. Applying this method to NiFe/graphene/NiFe MTJs, we achieve a 25-fold decrease in coercivity, aligning with the intrinsic properties of the magnetic contacts. By further integrating a NiO capping layer, we successfully restore magnetic anisotropy, resulting in a device performance comparable to traditional MTJs. Electrical and magnetoresistance measurements confirm improved sensitivity and energy efficiency, with sharp magnetoresistance slopes and high current density in pristine MTJs. Our results highlight the transformative potential of 2D materials in developing high-performance, low-coercivity spintronic devices, opening new opportunities for advanced magnetic sensing technologies and energy-efficient electronics.

Keywords: graphene, spintronics, coercivity, magnetic tunnel junction