Magnetic domain phase in van der Waals ferromagnet Fe₃GeTe₂ coupled to Co magnetic vortex

Van der Waals ferromagnet Fe₃GeTe₂ (FGT) is known to possess spontaneous chiral stripe domains which can be transformed into topological skyrmions under certain conditions. Using photoemission electron microscopy (PEEM), we imaged FGT magnetic domain phase under the influence of magnetic vortices. FGT flakes in contact with micron-sized Co disks across a spacer layer were fabricated by dry transfer method. We found that the vortex state of the Co disk melts the FGT stripes into elongated bubble states which resemble the liquid crystal phase. Thickness dependence of the interlayer coupling effect was also investigated on various thicknesses of FGT. Micromagnetic simulation via MuMax3 reproduced experimental phenomena. Our findings provide another novel spin texture phase in van der Waals magnetic materials.