  We study magnetization reversal and first order reversal curves for two
different magnetic topological semimetals, Co3Sn2S2 and Fe3GeTe2, in a wide
temperature range. For the magnetization reversal, we observe strong
temperature dependence of the initial (low-temperature) step-like magnetization
switchings, so the inverted hysteresis appears at high temperatures. Usually,
the inverted hysteresis is a fingerprint of material with two independent
magnetic phases, the inversion reflects the phase interaction. First order
reversal curve analysis confirms the two-phase behavior even at the lowest
temperatures of the experiment. While the bulk ferromagnetic magnetization
shows strong temperature dependence, one of the observed phases demonstrates
perfect stability below the Curie temperature. The obtained hysteresis loops
are of the bow-tie type, which is usually ascribed to appearance of the
skyrmionic phase. The described two-phase behavior is mostly identical for
Co3Sn2S2 and Fe3GeTe2 magnetic topological semimetals, only the characteristic
temperatures differ for these materials. The specifics of our experiment is the
excellent temperature stability of the second phase, while the skyrmions are
usually observed near the Curie temperature. On the other hand, temperature
stability can be expected for surface-state induced spin textures due to the
topological protection of surface states in topological semimetals. This also
explains the universal behavior of the second phase for two different
topological semimetals Co3Sn2S2 and FGT. Both these materials have strongly
different bulk properties, the only similarity is the presence of the
topological surface states. Thus, we can ascribe the second, temperature-stable
magnetic phase to the surface states in topological semimetals.
