Thickness dependent domain wall dynamics in Fe2CoSi thin films

Abstract

We report on the effect of thickness on the magnetic properties and domain wall motion in as deposited Fe2CoSi thin films. Reflections present in selected area electron diffraction (SAED) micrograph infer that they are allowed reflections and are related to the Fe2CoSi. The coercivity is found to increase with the film thickness and the same is explained on the basis of Néel domain wall model. Longitudinal magneto-optical Kerr effect (L – MOKE) infers that the formation of ripple kind of domains that depend on the orientation of the field. L – MOKE data also infers nearly perfect 4-fold anisotropy for the film with thickness 5 nm and a weaker 4-fold anisotropy at higher thicknesses. Up on varying the angle between magnetic field and the film edge to 0° or 90°, indeed there is a transformation of the film magnetization from easy direction to hard direction. Fast Fourier transform of magnetic force microscopy (MFM) and polar plots infer a uniaxial anisotropy and a four-fold anisotropy in the films. Micromagnetic simulations infer that the coercivity value depends on the void size and enhances up to certain radius, above which it decreases. Present results would indeed be helpful for the future spintronic applications.