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University of Nebraska - Lincoln

Ralph Skomski Publications

Series

2002

Articles 1 - 2 of 2

Full-Text Articles in Physics

Exact Nucleation Modes In Arrays Of Magnetic Particles, Ralph Skomski May 2002

Exact Nucleation Modes In Arrays Of Magnetic Particles, Ralph Skomski

Ralph Skomski Publications

Magnetization reversal in arrays of magnetic nanoparticles with perpendicular anisotropy is investigated. Aside from domain-wall propagation effects, the reversal involves two main aspects: the nucleation behavior of individual particles and interparticle interactions. Due to magnetostatic self-interaction effects, the interparticle interaction cannot be reduced to a stray-field correction to the external field. Exact nucleation fields and explicit stray-field and self-interaction contributions are obtained for rings of equidistant dots. An exact treatment of self-interactions in various structurally inhomogeneous but rotationally symmetric wire, sphere, and thin-film nanostructures leads to renormalization of the uniaxial anisotropy. Finally, an approximate method to calculate nucleation fields is …


Exchange-Controlled Magnetic Anisotropy, Ralph Skomski May 2002

Exchange-Controlled Magnetic Anisotropy, Ralph Skomski

Ralph Skomski Publications

The magnetocrystalline anisotropy of 5f transition-metal atoms (actinides) is investigated. A simple model Hamiltonian reproduces the observed huge low-temperature anisotropy of cubic actinide compounds such as US and predicts the temperature dependence of the anisotropy. The dominance of the spin–orbit and crystal–field interactions means that the magnitude of the anisotropy is limited only by interatomic exchange. One consequence is that cubic and uniaxial 4f magnets have similar magnitudes of the anisotropy and similar temperatures dependencies.