Magnetic localization in transition-metal nanowires

TLDR

Localization of magnetization reversal is a general phenomenon caused by morphological inhomogeneities in both polycrystalline and single‑crystalline transition‑metal nanowires. The study investigates magnetization reversal in transition‑metal nanowires. The authors model reversal by analyzing exchange–anisotropy competition in polycrystalline wires, weak nucleation localization in single‑crystalline wires, and predicting coercive and magnetic‑viscosity behavior of Co and Ni nanowires electrodeposited in alumina pores. Model calculations show that reversal is localized rather than delocalized coherent‑rotation or curling, explaining the observed behavior.

Abstract

Magnetization reversal in transition-metal nanowires is investigated. Model calculations explain why magnetization reversal is localized, as opposed to the sometimes assumed delocalized coherent-rotation and curling modes. The localization is a quite general phenomenon caused by morphological inhomogenities and occurring in both polycrystalline and single-crystalline wires. In the polycrystalline limit, the competition between interatomic exchange and anisotropy gives rise to a variety of random-anisotropy effects, whereas nearly single-crystalline wires exhibit a weak localization of the nucleation mode. Model predictions are used to explain the coercive and magnetic-viscosity behavior of Co (and Ni) nanowires electrodeposited in self-assembled alumina pores.