Uniform excitations in magnetic nanoparticles

• Steen Mørup,
• Cathrine Frandsen and
• Mikkel Fougt Hansen

Beilstein J. Nanotechnol. 2010, 1, 48–54, doi:10.3762/bjnano.1.6

• inelastic neutron scattering. Keywords: collective magnetic excitations; Mössbauer spectroscopy; neutron scattering; spin waves; superparamagnetic relaxation; Review Introduction One of the most important differences between magnetic nanoparticles and the corresponding bulk materials is that the magnetic

• , superparamagnetic relaxation can be considered negligible, but the magnetization direction may still fluctuate in directions close to the easy axes at θ = 0° and θ = 180°. These fluctuations have been termed “collective magnetic excitations” [3][4][5]. The magnetic excitations in a nanoparticle are illustrated

• described in terms of excitations of the uniform mode in combination with transitions between excited states with different values of n0, i.e., with different precession angles. These dynamics have also been termed “collective magnetic excitations” [4][5]. The contribution from the uniform mode to the