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

DOI: 10.1021/acsami.0c14058

Authors: Maciej Dabrowski (University of Exeter) , Andreas Frisk (Diamond Light Source) , David M. Burn (Diamond Light Source) , David G. Newman (University of Exeter) , Christoph Klewe (Advanced Light Source) , Alpha T. N’diaye (Advanced Light Source) , Padraic Shafer (Advanced Light Source) , Elke Arenholz (Advanced Light Source; Cornell High Energy Synchrotron Source) , Graham J. Bowden (University of Southampton) , Thorsten Hesjedal (University of Oxford) , Gerrit Van Der Laan (Diamond Light Source) , Gino Hrkac (University of Exeter) , Robert J. Hicken (University of Exeter)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Acs Applied Materials & Interfaces

State: Published (Approved)
Published: November 2020
Diamond Proposal Number(s): 17745 , 19116 , 20760

Abstract: Microwave and heat-assisted magnetic recordings 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.

Journal Keywords: interfacial domains; exchange spring magnets; ferromagnetic resonance; time-resolved magneto-optical Kerr effect (TRMOKE); X-ray magnetic circular

Subject Areas: Materials, Physics


Instruments: I10-Beamline for Advanced Dichroism

Other Facilities: Beamlines 4.0.2 at ALS