Exchange bias effect in the martensitic state of Ni-Co-Mn-Sn film

摘要

We report a relatively large exchange bias (EB) effect in epitaxially grown Ni-Co-Mn-Sn film. EB effect has been observed at low temperature below 60 K with a maximum EB field of 139 Oe at 5 K which is high compared to Ni-Mn-Sn thin films. Systematic studies on the magnetic properties show that both EB field and coercivity decreased with increase in temperature. Martensitic transformation at room temperature was confirmed from the atomic force microscopy micrograph exhibiting twin pattern. The observed EB behavior in Ni_(45.0)Co_(4.4)Mn_(41.5) Sn_(9.1) film is attributed to the coexistence of antiferromagnetic and ferromagnetic exchange interactions in the system.