  The materials exhibiting exchange bias (EB) have been extensively
investigated mainly due to their great technological applications in magnetic
sensors, but its underlying mechanism remains elusive. Here we report the novel
coexistence of in-plane and out-of-plane EB in the Cr-doped Mn3Sn, a
non-colinear antiferromagnet with a geometrically frustrated Kagome plane of
Mn. Field-cooling experiments with the applied field parallel and perpendicular
to the frustrated Kagome plane exhibits loop shifts and enhanced coercivities.
Interestingly, a maximum EB field of 1090 Oe is observed along out-of-plane
direction in the Mn2.58Cr0.42Sn sample, higher than that of in-plane value. Our
results indicate that the exchange bias along perpendicular kagome plane is
primarily induced by Dzyaloshinskii-Moriya interactions due to the breaking of
interfacial symmetry, while the EB along kagome plane is due to the exchange
effects at interface of AFM and FM component originating from the net moment.
These findings provide a new insight on EB in the kagome AFM materials, which
are important and highly potential to the application of antiferromagnetic
spintronics.
