Enhanced antiferromagnetic resonance linewidth in NiO/Pt and NiO/Pd

In this paper, we investigate the enhancement of the antiferromagnetic damping in the sintered NiO-HM (where HM is heavy metal) granular systems having NiO/HM interfaces, where HM=Pt or Pd. Under the assumption of the spin pumping model, we derive the effective interfacial damping conductance geff, the parameter which characterizes the upper-bound estimate of the spin pumping effect, to be 12±1nm−2 and 5±1nm−2 for the NiO/Pt and the NiO/Pd interfaces, respectively, at room temperature. geff experimentally derived in this study are an important milestone in antiferromagnetic spintronics, giving a guideline for various spin current transfer and spin interaction phenomena with antiferromagnets where the spin mixing conductance is involved.