Magnetic Moment Softening and Domain Wall Resistance in Ni Nanowires

Abstract

Magnetic moments in atomic scale domain walls formed in nanoconstrictions and nanowires are softened which affects dramatically the domain wall resistance. We perform ab initio calculations of the electronic structure and conductance of atomic-size Ni nanowires with domain walls only a few atomic lattice constants wide. We show that the hybridization between noncollinear spin states leads to a reduction of the magnetic moments in the domain wall. This magnetic moment softening strongly enhances the domain wall resistance due to scattering produced by the local perturbation of the electronic potential.

Fully relaxed magnetic structure of transition metal nanowires: First-principles calculations

“…The increase of the moments in the center of the wire is a geometrical effect originating from the coexistence of bulk-like ͑three dimensions͒ behavior far in the leads, and reduced dimensionality at the lead surfaces ͑two dimensions͒, and in the nanowire ͑one dimension͒ between the leads. For this reason, the effect was not observed by Burton et al, 18 who considered a DW in a freestanding wire. At the same time, a small reduction of the moments inside the DW for the antiparallel alignment relative to the parallel one is certainly similar to the "magnetic moment softening" discussed by these authors.…”

“…For the atoms in the wall, they used bulk potentials properly transformed in the spin subspace. Burton et al 18 reported DW resistance in Ni wires based on ab initio electronic structure calculations. The nanoconstriction was modeled by freestanding monatomic wires and wires with a cross section of 5 ϫ 4 atoms.…”

Quantized magnetoresistance in atomic-size contacts

“…S4), as has also been found by others 21 . A possible explanation for the absence of quantized conductance in Ni contacts is the weakened magnetism of Ni in constrained geometries 28 .…”

Ni/Ni3C Core–Shell Nanochains and Its Magnetic Properties: One-Step Synthesis at Low Temperature

“…[1][2][3][4] In addition, some of the basic issues about magnetic and optical phenomena in one-dimensional systems have also been addressed with these materials. 4,5 Accordingly, a series of one-dimension (1D) nickel nanostructures including nanotubes, nanowires, nanorods, nanochains and nanoarrays have been synthesized. [6][7][8][9][10][11][12][13] A variety of one-dimensional (1D) core-shell structures were prepared to enhance the multifunctionality of these materials, and they have exhibited good characters in improving luminescent efficiency, magnetic property and as field effect transistors.…”