Effect of the Pt buffer layer on perpendicular exchange bias based on collinear/non-collinear coupling in a Cr₂O₃/Co₃Pt interface

In this study, we fabricated a Cr₂O₃ (0001) film without and with a Pt buffer layer and investigated its effect on perpendicular exchange coupling in a Cr₂O₃/Co₃Pt interface. The results showed that the exchange bias field (μ₀H_ex) and blocking temperature (T_B) of a Cr₂O₃ film without and with Pt were very different. The Cr₂O₃ film without Pt had a lower μ₀H_ex of 176 Oe and a lower T_B of 75 K, whereas that with Pt had a higher μ₀H_ex of 436 Oe and a higher T_B of 150 K. We discussed this difference in μ₀H_ex and T_B values based on collinear/non-collinear coupling in a ferromagnetic and antiferromagnetic interface using Meiklejohn and Bean's exchange anisotropy model.