  Owing to the experimental discovery of magnetic skyrmions stabilized by the
Dzyaloshinskii-Moriya and/or dipolar interactions in thin films, there is a
recent upsurge of interest in magnetic skyrmions with antiferromagnetic spins
in order to overcome the fundamental limitations inherent with skyrmions in
ferromagnetic materials. Here, we report on the observation of compact
ferrimagnetic skyrmions for the class of amorphous alloys consisting of 4f
rare-earth and 3d transition-metal elements with perpendicular magnetic
anisotropy, using a DyCo$_3$ film, that are identified by combining x-ray
magnetic scattering, scanning transmission x-ray microscopy, and Hall transport
technique. These skyrmions, with antiparallel aligned Dy and Co magnetic
moments and a characteristic core radius of about 40~nm, are formed during the
nucleation and annihilation of the magnetic maze-like domain pattern exhibiting
a topological Hall effect contribution. Our findings provide a promising route
for fundamental research in the field of ferrimagnetic/antiferromagnetic
spintronics towards practical applications.
