Tunable Magnetic Vortex Dynamics in Ion-Implanted Permalloy Disks

• DOI: 10.1021/acsami.0c08024
• Publication Date: 2020-05-22T21:41:45Z
• Authors: Lakshmi Ramasubra...; Attila Kákay; Ciarán Fowley; Oguz Yildirim; Patrick Matthes; Serhii Sorokin; Aleksandra Titova; Donovan Hilliard; Roman Böttger; René Hübner; Sibylle Gemming; Stefan E. Schulz; Florian Kronast; Denys Makarov; Jürgen Fassbender; Alina Deac
• Keywords: Permalloy

Nanoscale, low-phase-noise, tunable transmitter–receiver links are key for enabling the progress of wireless communication. We demonstrate that vortex-based spin-torque nano-oscillators, which intrinsically low-noise devices because their topologically protected magnetic structure, can achieve frequency tunability when submitted to local ion implantation. In experiments presented here, gyrotropic mode is excited with spin-polarized alternating currents and anisotropic magnetoresistance measurements yield discrete frequencies from a single device. Indeed, chromium-implanted regions permalloy disks exhibit different saturation magnetization than neighboring, non-irradiated areas, thus resonance frequency, corresponding specific area where core gyrating. Our study proves such be fabricated without need further lithographical steps, suggesting irradiation viable cost-effective fabrication method densely packed networks oscillators.