Evidence for vortex state in Fe2CoGe thin films using FORC and magnetic imaging

We report on the evidence for the vortex state in the thin films of Fe ₂CoGe through first order reversal curves, magnetic force microscope, longitudinal magneto-optical Kerr effect and micro-magnetic simulations. Phase purity of the films confirmed through X-ray diffraction, which confirms the A2 type disorder Heusler alloy structure. Contour graph of first order reversal curves infers the formation of vortex state that is useful to understand magnetization reversal and switching process. We do observe the vortex state ∼1 μm with in – plane curling of the magnetization using magnetic force microscope phase analysis. We believe that realization of vortex state formation in Fe ₂ CoGe thin films may cater applications in future magnetic data storage and microwave oscillators.