Magnetic Aromaticity of Cycloporphyrin Nanorings

Metastable states in magnetic nanorings

Magnetization states and hysteresis behavior of small ferromagnetic rings, of diameters 180–520 nm, have been investigated using magnetic force microscopy. In addition to the expected bi-domain ~‘‘onion’’! and flux-closed ~‘‘vortex’’! magnetization states, a metastable state has been found. This ‘‘twisted’’ state contains a 360° domain wall which can exist over a wide range of applied fields. F...

Synthesis and Characterization of Magnetic Nanorings for Neuronal Stimulation

Large-scale synthesis of single-crystalline iron oxide magnetic nanorings.

We present an innovative approach to the production of single-crystal iron oxide nanorings employing a solution-based route. Single-crystal hematite (alpha-Fe2O3) nanorings were synthesized using a double anion-assisted hydrothermal method (involving phosphate and sulfate ions), which can be divided into two stages: (1) formation of capsule-shaped alpha-Fe2O3 nanoparticles and (2) preferential ...

Cobalt ferrite nanorings: Ostwald ripening dictated synthesis and magnetic properties.

CoFe(2)O(4) nanorings were synthesized by a simple solvothermal process, in which Ostwald ripening was definitely responsible for the formation of hollow structures, and their ferromagnetic behavior at room temperature was observed.

Ferromagnetic nanorings

Ferromagnetic metal rings of nanometre range widths and thicknesses exhibit fundamentally new spin states, switching behaviour and spin dynamics, which can be precisely controlled via geometry, material composition and applied f eld. Following the discovery of the ‘onion state’, which mediates the switching to and between vortex states, a range of fascinating phenomena has been found in these s...