Spin current transmission in polycrystalline NiO films

Abstract

Spin current transmission in antiferromagnetic materials is one of the important and intriguing problems in the recently emerged field of antiferromagnetic spintronics. We investigate the spin current transmission in polycrystalline NiO by referencing the effective Gilbert damping constant in NiO/FeNi bilayers. The results are discussed with reference to the spin pumping theory assuming that the NiO layer is spin diffusive. We extracted the spin diffusion length of ∼22 nm for the NiO and the mixing conductance of ∼6 nm−2 at the NiO/FeNi interface. The obtained spin diffusion length and the mixing conductance are within reasonable ranges compared with previous reports.