Magnetization dynamics damping

Figure 12. Magnetization dynamics of a nanoparticle (a) damped precession and (b) random...

The relaxation time Xg in Eq.7 is also called the damping time, empirically derived values that are obtained by fitting data to phenomenological models for magnetization dynamics. The most widely cited of these models is that of Landau and Lifshitz (1935),... 

Improved rotor dynamic stability. The active magnetic bearing s ability to vary stiffness and damping permits rotation about the rotor s inertial axis, eliminating vibration and noise. 

Nagaya, K., and Kojima, H. (1984). On a magnetic damper consisting of a circular magnetic flux and a conductor of arbitrary shape. Part I Derivation of the damping coefficients. Transactions of the ASME J. Dynam. Syst. Meets. Control. 106, 46-51. 

Solvent can affect the electronic structure of the solute and, hence, its magnetic properties either directly (e.g. favouring more polar resonance forms) or indirectly through geometry changes. Furthermore, it can influence the dynamical behaviour of the molecule for example, viscous and/or oriented solvents (such as liquid crystals) can strongly damp the rotational and vibrational motions of the radical. Static aspects will be treated in the following, whereas the last aspect will be tackled in the section devoted to all the dynamical effects. 

Dynamic micromagnetics simulations show that shape, size, and damping constant significantly influence the switching behavior of thin film elements. The magnetization reversal of submicron NiFe elements was found to be a two stage process. At first, the magnetization rotates almost in plane towards... 

In order to assess magnetization transfer in a multiple-spin system, it is necessary to define a measure that reflects the efficiency of the transfer between two spins i and j. This parameter should reflect the amplitude of the ideal polarization transfer as well as the duration of the mixing process, because, in practice, Hartmann-Hahn transfer competes with relaxation. Relaxation effects result in a damping of the ideal polarization-transfer functions 7j . The damping due to relaxation depends not only on the structure and dynamics of the molecule that hosts the spin system of interest, but also on the actual trajectories of polarizations and coherences under a specific multiple-pulse Hartmann-Hahn mixing sequence (see Section IV.D). For specific sample conditions and a specific experiment, the coherence-transfer efficiency can be defined as the maximum of the damped magnetization-transfer function. 

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