Uniaxial anisotropy separation

In the case of Co—Cr having perpendicular anisotropy there is, in principle, a competition between the uniaxial anisotropy of a hexagonal stmcture and the demagnetizing energy of the thin film. In the case of magnetically separated Co—Cr columns (particulate morphology) then also the shape anisotropy contributes to the perpendicular anisotropy. 

The spherical harmonic analysis so far presented for uniaxial anisotropy is mainly concerned with the relaxation in a direction parallel to the easy axis of the uniaxial anisotropy. We have not considered in detail the behavior resulting from the transverse application of an external field and the relaxation in that direction for uniaxial anisotropy. Thus we have only considered potentials of the form V(r, t) = V(i, t) where the azimuthal or dependence in Brown s equation is irrelevant to the calculation of the relaxation times. This has simplified the reduction of that equation to a set of differential-difference equations. In this section we consider the reduction when the azimuthal dependence is included. This is of importance in the transition of the system from magnetic relaxation to ferromagnetic resonance. The original study [17] was made using the method of separation of variables on Brown s equation which reduced the solution to an eigenvalue problem. We reconsider the solution by casting... 

Magnetic anisotropy data are reported, where available, as special inserts into the tables. Likewise, principal molar susceptibilities X1.Z2.Z3 listed and, for monoclinic crystals, angles and 0 are noted. In the case of uniaxial systems, we use x,=x2=Xj. and Z3 = Zii- Where principal molecular susceptibilities Ku K2, Ki have been determined, these are reported as separate inserts into the tables. The temperature variation of the principal molar susceptibilities is listed, where such data were available in the literature. In some cases, where the temperature dependence follows the Curie-Weiss law Eq. (26), the constants p and 0p for the magnetic axes 1,2 and 3 are given. 

The principal axes of the molecular polarizability tensor are labelled /, m, n, as shown in Fig. 2. Thus the importance of order parameters in determining the anisotropy of optical properties is clearly demonstrated. Both order parameters S and D contribute to the anisotropy of second rank tensor properties even in uniaxial liquid crystals, but they cannot be separated from a single measurement of the birefringence. 

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