Anisotropic Exchange Stiffness Constant of Exchange Biased MnIr/NiFe Thin Film

The ferromagnetic resonance field and spin wave resonance field with in-plane angles. H were measured in order to analyze the angular dependence of exchange stiffness constant A(ex) in exchange biased MnIr/NiFe thin film. The A(ex) of MnIr/NiFe thin film showed an anisotropic behavior such as A ex = A(0) + A(eb)cos Phi(H). The isotropic exchange stiffness constant A(0) was due to the exchange stiffness constant of NiFe, while anisotropic exchange stiffness constant A(eb) was due to the exchange bias field.