We have used density functional theory within spin-polarized local density approximation to investigate the equilibrium structure, electronic, and magnetic properties of one-dimensional Ni/Cu and Ni/Al multilayered nanowires. In particular, we look into the subtle changes in the magnetic properties of the nanowires with the change in the width of the nonmagnetic spacer. Our calculations yield the magnitude of cohesive energy in both the systems to decrease with the increase in the concentration of the nonmagnetic spacer, suggesting that Ni rich nanowires are more stable. Analysis of the magnetic moment per Ni atom (μav) in the Ni/Cu hybrid multilayered nanowire suggests that there is a steady decrease in μav with the increase in the number of Cu layers. In contrast, in Ni/Al multilayered nanowire, there is a nonmonotonic decrease in μav with the increase in Al layers. The observed difference in magnetic property between Ni/Cu and Ni/Al multilayered nanowires is attributed to the dissimilar interfacial bonding in the two cases. In the case of Ni/Al nanowire, the nonmonotonic variation in μav is due to the strong directional nature of the Ni d and Al p hybridization, which favors Ni to have higher coordination number. Higher coordination for Ni leads to smaller μav in the Ni/Al multilayered nanowire. However, the hybridization between Ni d and Cu s states is predominantly responsible for the smaller μav in the Ni/Cu nanowire. Furthermore, we found that in Ni/Al multilayered nanowire with two Al spacer layer, the antiferromagnetic configuration is favored over ferromagnetic configuration. In Ni/Cu multilayered nanowire, ferromagnetic configuration is favored over antiferromagnetic configuration for the same spacer length
Physical Review B
Pal, P. P.,
Magnetic properties of one-dimensional Ni/Cu and Ni/Al multilayered nanowires: Role of nonmagnetic spacers.
Physical Review B,
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