Optically and microwave-induced magnetization precession in [Co/Pt]/NiFe exchange springs

Journal article

Microwave and heat assisted magnetic recording are two competing technologies that have greatly increased the capacity of hard disk drives. The efficiency of the magnetic recording process can be further improved by employing non-collinear spin structures that combine perpendicular and in-plane magnetic anisotropy. Here, we investigate both microwave and optically excited magnetization dynamics in [Co/Pt]/NiFe exchange spring samples. The resulting canted magnetization within the nanoscale [Co/Pt]/NiFe interfacial region allows for optically stimulated magnetization precession to be observed for an extended magnetic field and frequency range. The results can be explained by formation of an imprinted domain structure, which locks the magnetization orientation and makes the structures more robust against external perturbations. Tuning the canted interfacial domain structure may provide greater control of optically excited magnetization reversal and optically generated spin currents, which are of paramount importance for future ultrafast magnetic recording and spintronic applications.

Authors: Dabrowski, M; Frisk, A; Burn, D; Newman, D; Klewe, C

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: American Chemical Society
• Journal: ACS Applied Materials and Interfaces
• Volume: 12
• Issue: 46
• Pages: 52116-52124
• Publication date: 2020-11-06
• Acceptance date: 2020-10-23
• DOI: 10.1021/acsami.0c14058
• EISSN: 1944-8252
• ISSN: 1944-8244
• Language: English
• Keywords: exchange spring magnets; FFR; x-ray magnetic circular dichroism (XMCD); interfacial domains; spin transfer torque (STT); time resolved magneto-optical Kerr effect (TRMOKE); ferromagnetic resonance; xray detected ferromagnetic resonance (XFMR)