[16p-S4_201-13~19] 10.3 Spin devices, magnetic memories and storages

5:45 PM - 6:00 PM JST(8:45 AM - 9:00 AM UTC)Presentation by Applicant for JSAP Young Scientists Presentation AwardEnglish Presentation

[16p-S4_201-15] Efficient magnetization switching driven by spin–orbital torque in light 3d transition-metal nitrides

〇(P)GAURAV KUMAR SHUKLA¹, PRABHAT Kumar¹, Mayank K. Singh¹, Shinji Isogami¹ (1.NIMS)

Keywords:

Spin-orbit torque,Magnetic memory device,Light metal systems

Orbitronics, based on the orbital Hall effect (OHE) in light metals, offers a promising route toward energy-efficient current-driven magnetization switching. Inspired by recent OHE-driven switching in Cr₂N MXene, we explore light transition-metal nitrides (MN; M = Cr, V, Ti) as efficient orbital current sources for spin-orbit torque (SOT) devices. We fabricate Al₂O₃//MN/[Co/Pt]₃/MgO heterostructures, where the (111)-oriented fcc MN layers possess alternating metal and nitrogen stacking, analogous to Cr₂N. CrN/[Co/Pt]₃ exhibits a low switching current density of ~2.6 MA/cm² with a torque efficiency of 0.18. VN shows a large negative torque efficiency (–0.16), strongly dependent on the ferromagnetic layer, indicating dominant orbital current generation, with reduced switching current at increased VN thickness. First-principles calculations confirm that VN has a significantly larger orbital Hall conductivity than spin Hall conductivity. TiN/[Co/Pt]₃ demonstrates an exceptionally large damping-like torque efficiency (–0.52) and a switching current density of ~7 MA/cm², comparable to heavy-metal-based SOT systems.