Holographic imaging of interlayer coupling in Co/Pt/NiFe

Thomas A. Duckworth (1) , Feodor Y. Ogrin (1) , Guillaume Beutier (2) , Sarnjeet S. Dhesi (3) , Stuart A. Cavill (3) , Sean Langridge (4) , Amy Whiteside (5) , Thomas Moore (5) , Maxime Dupraz (2) , Flora Yakhou (6) , Gerrit van Der Laan (3)

1 University of Exeter
2 SIMaP - Science et Ingénierie des Matériaux et Procédés
3 DIAMOND Light source
4 ISIS Facility
5 University of Leeds
6 ESRF - European Synchrotron Radiation Facility

We present a method to determine the magnetic configuration of an in-plane magnetized permalloy layer using Fourier transform holography with extended references in an off-normal geometry. We use a narrow slit as an extended holographic reference to record holograms with the sample surface orthogonal to the incident x-ray beam, as well as rotated by 30° and 45° with respect to the beam. To demonstrate the sensitivity of the technique to in-plane magnetization, we present images of flux closed ground states in thin (∼50 nm) permalloy elements, less than 1 μm in lateral size. Images of the in-plane domain pattern which is magnetostatically imprinted into a permalloy film by the stray fields generated by an adjacent Co/Pt multilayer were obtained. It is found that, whilst the domain patterns within the two magnetic layers show a strong resemblance at remanence within a pristine sample, the similarities disappear after the sample is exposed to a saturating magnetic field.

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Thomas A. Duckworth, Feodor Y. Ogrin, Guillaume Beutier, Sarnjeet S. Dhesi, Stuart A. Cavill, et al.. Holographic imaging of interlayer coupling in Co/Pt/NiFe. New Journal of Physics, 2013, 15, pp.3045. ⟨10.1088/1367-2630/15/2/023045⟩. ⟨hal-00802398⟩