Electrical conductance studies of synthetic antiferromagnet based spin-valves

Abstract

The electrical properties of synthetic spin-valves comprising CoFe/Ru/CoFe/Cu/NiFe have been studied by using the linear Boltzmann equation with relaxation time approximation. It is found that most of the current is carried by the Cu and ferromagnetic layers in the spin-valves when Ta is used as the capping and seed layer. The current density distribution is spin dependent which results in the giant magnetoresistance effect. The GMR ratio depends on a lot of parameters, such as the thickness of the ferromagnetic layers, the spin asymmetry scattering coefficients both within ferromagnetic layers and at the interface between ferromagnetic and nonmagnetic layers, as well as on the specularity factor of the seed and capping layers. Both material quality improvement and structural optimization needs to be taken into account in order to realize higher performance spin valve read heads.