  The exchange bias (EB) effect, pivotal in magnetic data storage and sensing
devices, has been observed not only in interfacial regions but also in
intrinsic ferromagnetic materials. Here, we've uncovered a robust and stable
exchange bias effect within the layered van der Waals (vdW) ferromagnet VI3
employing magnetic circular dichroism microscopy. At 10 K, we observed a
significant exchange field of approximately 0.1 T, accompanied by random shifts
(positive or negative relative to zero magnetic field) after zero-field
cooling. Notably, this effect is effectively controllable after field cooling,
with shift direction opposing the applied magnetic field. The presence of
strong magnetic anisotropic energy within VI3 results in larger
coercivity-bound magnetic domains. These domains dictate the neighboring
ferromagnetic alignment and induce shifts in the hysteresis loop. Our study not
only contributes to comprehending fundamental nanoscale magnetic interactions
but also sheds light on emergent phenomena within layered van der Waals
magnets.
