Quality factor ferrites

This relaxation time—which, to be specific, we have written in the Landau-Lifshitz representation—has the anticipated behavior the smaller the precession damping constant (the higher the quality factor of the oscillations), the slower does the particle magnetic moment approach its equilibrium position. For ferromagnet or ferrite nanoparticles the typical values of the material parameters are Is Is < 103G, Vm 10 18cm3, and a 0.1. Substituting them in formula (4.28) aty 2 x 108 rad/Oe s and room temperature, one obtains xD 10-9 s. 

As discussed in Section 9.3.1, the quality of the ferrite is measured by its loss factor (tan <5)//tri which should be as small as possible, and in the following discussion it is assumed that this is the case. 

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