The effect of microstructure and interface conditions on the anisotropic exchange fields of NiO/NiFe

We have investigated the effect of microstructure and interface conditions on the anisotropic exchange fields of NiO/NiFe bilayers. The NiO films were deposited by dc magnetron reactive sputtering. By using different substrates or annealing NiO films, grain size and surface roughness of NiO can be manipulated. The exchange field is enhanced in the small-grained NiO and this enhancement is attributed to the formation of small domains in NiO. The degree of interfacial roughness and the existence of (111) texture showed no correlation with exchange field.