Temperature dependence of exchange anisotropy for (001) oriented Mn89Pt11/ferromagnetic bilayers

Abstract: Temperature dependence of the exchange anisotropy was investigated for (001)-oriented top-type Mn89Pt11 (t AF nm)/Ni80Fe20 (5nm) and bottom-type Ni80Fe20 (3nm)/Mn89Pt11 (30nm) and Co90Fe10 (3nm)/Mn89Pt11 (30nm) bilayers. The top-type MnPt/NiFe bilayers exhibited both 1 and 4-fold anisotropies in their in-plane torque curves at 80K. For t AF=3nm, rapid decrease of 1-fold component and gradual decrease of 4-fold component were observed with increasing temperature. While for t AF=30nm, 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. [Copyright &y& Elsevier]