Magnetic profiles

The magnetization profile in the y-direction is recovered by Fourier transfonnation with respect to G. B1.14.2.4 2D SPIN-ECHO FT IMAGING AND K-SPACE... 

Table 9. Magnetic profiles of CoNiReP films (T. Osaka et al., 1991 [116]).

Fig. 46. Schematic order parameter (magnetization) profiles m(z) near a free surface, according to mean field theory. Various cases arc shown (a) Extrapolation length X positive. The transition of the surface from the disordered state to the ordered state is driven by the transition in the bulk ( ordinary transition ). The shaded area indicates the definition of the surface magnetization ms. (b) Extrapolation length X = oo. The transition of the surface is called "special transition ( surfacc-bulk-multicritical point ), (c), (d) Extrapolation length X < 0, temperature above the bulk critical temperature (c) or below it (d). The transition between states (c) and (d) is called the extraordinary transition , (c) Surface magnetic field Hi competes with bulk order (mi, > 0, 0 < H such that mi < -mb). In this case a domain of oppositely oriented magnetization with macroscopic thickness ( welting layer ) separated by an interface from the bulk would form at the surface, ir the system is at the coexistence curve (T < Tv, H = 0). From Binder (1983).

Fig. 50. Magnetization profiles across thin Ising films [eq. (1) with H — H — 0], upper part, and near the surface of semi-infinite Heisenberg ferromagnels, lower part (where bulk behavior in the Monte Carlo simulation is enforced by an effective field boundary condition at z — 16). Note that in the Ising case (where three film thicknesses L = 5, 10, and 20 are shown) the surface layer magnetization m- — m(z — 0) is independent of L, and for L > 10 already the bulk value of the order parameter is reached in the center of the film. For the Heisenberg model, on the other hand, at a comparable temperature distance from % the free surface produces a Long-range perturbation of the local magnetization m(z). From Binder and Hohenbcrg (1974).

Figure 10. Magnetic profile along ground surface traverse, X-X, and the local anomaly created by buried drums.

The magnetization profile in the y-direction is recovered by Fourier transformation with respect to Gy. 

Profiling steam boxes and infrared and magnetic profilers are some of the devices utilized in paper machines. 

The magnetic profiler uses independently exited electromagnets installed across the width of a dryer cylinder. As the cylinder, which is a conductor, passes through the magnetic flux lines, eddy currents (which produce heat) are induced in the shell. This heat provides very precise and discrete control of the moisture profile. The eddy current heating produced can be 100 times higher than the input power to the inductor in the 150-mm width band. Commercial tests show that these profilers control the moisture within h-0.3% and increase the machine speed up to 5%-10% [48]. 

The Butcher-Ridge structure gives rise to a strong magnetic anomaly which is not compatible with a typical sill of Ferrar Dolerite. Instead, Behrendt et al. (1995) concluded that the magnetic profile, which peaks... 

P. Czemer, U. Ritschel, Magnetization profile in the D=2 semiinfinite Ising model and crossover between ordinary and normal transition, Int. J. Mod. Phys. B 11 (1997) 2075-2091. 

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