Temperature dependence of exchange anisotropy for (0 0 1) oriented Mn89Pt11/ferromagnetic bilayers

Abstract Temperature dependence of the exchange anisotropy was investigated for (0 0 1)-oriented top-type Mn 89 Pt 11 ( t AF nm)/Ni 80 Fe 20 (5 nm) and bottom-type Ni 80 Fe 20 (3 nm)/Mn 89 Pt 11 (30 nm) and Co 90 Fe 10 (3 nm)/Mn 89 Pt 11 (30 nm) bilayers. The top-type MnPt/NiFe bilayers exhibited both 1 and 4-fold anisotropies in their in-plane torque curves at 80 K. For t AF =3 nm, rapid decrease of 1-fold component and gradual decrease of 4-fold component were observed with increasing temperature. While for t AF =30 nm, the 1 and 4-fold anisotropies decreased similarly with temperature. In the bottom-type bilayers, by using CoFe ferromagnetic layer, the 4-fold anisotropy was found to become twice as that of the NiFe/MnPt bilayer.