Antiferromagnetic energy loss and exchange coupling of IrMn/CoFe films: experiments and simulations

Abstract The energy loss density E 2 π and the coupling energy density J of antiferromagnetic (1 1 1) textured IrMn films of different thickness t sputtered onto ferromagnetic CoFe films have been measured by torque magnetometry for high in-plane rotating magnetic fields at a low temperature ( T =10 K). The results are compared with model calculations which assume independent grains of equal size with a statistical distribution of individual grain coupling energies. Analytical expressions for E 2 π ( t ) and J ( t ) are used to explain the measurements for small thicknesses t K ( t ) is introduced. At t =3 nm, K ≈1.3×10 5 J/m 3 .