Switching field

Switching-Field Distribution. Both and have a strong relation with the recording process. determines the maximum output signal of a recording medium and hence the signal-to-noise ratio. ascertains how easily data can be recorded and erased or changed, but it also determines the maximum head field. On the other hand it also controls the ease with which data can be destroyed, eg, by stray fields. The lower the the more sensitive the medium is to all kinds of fields. In this way, influences the noise level as well. The squareness ratio S (= /Af ) can also be derived from the... 

This critical field called coercivity or switching field is also equal to If a field is appHed in between 0 and 90° the coercivity varies from maximum to zero. In the case of this special example the appHed field = H/. Based on the classical theory, Stoner-Wohlfarth (33)... 

Fig. 8. Giant negative magnetoiesistance RjR H = 0) behavioi of three Fe/Ci superlattices as a function of applied field at 4.2 K showing the value of the complete switching field, for each lattice. The current and the appHed field are along the (110) direction ia the plane of the layers (60). To convert T to...

Fe/Ci variable ((001) Fe/Cr(001)), 0.9—9.0-nm single-crystal layer thick-ness on single-crystal GaAs resistivity lowered by as much as a factor of two at 4.2 K and switching fields of the order of 1 T are requited 60,61... 

Figure 8.20 TbPc 2 SIM and NEMS based resonator [258]. (a) The magnetization reversal of the Tb3+ ion induced by sweeping the magnetic field parallel to the easy axis of the SMM, resulted in an abrupt increase in the differential conductance through the SW-CNT of NEMS. The switching field depends on the nuclear spin state occupied before magnetization reversal, (b) Elistogram of...

Figure 3.32 Hysteresis behavior of the magnetization of a ferromagnetic crystal or polarization of a ferroelectric crystal with respect to the applied magnetic or electric switching field.

There are a variety of models for the magnetic field dependence for polymers and variously ordered phases coming largely from the groups of Kimmich and Noack. We focus here on the protein system that provides unique structural and physical characteristics. Recent advances in the speed of current-switched field-cycling instruments have provided a direct measure of the MRD profile of the protein protons as shown in Fig. 18. The relaxation... 

According to the second law, (W) = Q) > 0, which implies that the average switching field is positive, (// ) > 0 (as expected due to the time lag between the reversal of the field and the reversal of the dipole). The work distribution is just given by the switching field distribution p H ). This is a quantity easy to compute. The probability that the dipole is in the down state at field H satisfies a master equation that only includes the death process,... 

Fe/Cr var ((00l) Fe/Cr(0Ol))H, 0.9-9.0-nm single-crystal layer thickness on single-crystal GaAs resistivity lowered by factor of 2 at 4.2 K, switching fields on order of 1 T req d... 

This critical field called coercivity ff. or switching field Ff., is also equal to FF. If a field is applied in between 0 and 90° the coercivity varies from maximum to zero. In the case of this special example the applied field Ha = Hs = Hc = Hk. Based on the classical theory, Stoner-Wohlfarth (33) considered the rotation unison for noninteracted, randomly oriented, elongated particles. The anisotropic axis can be due to the shape anisotropy (depending on the size and shape of the particle) or to the crystalline anisotropy. In the prolate ellipsoids b is the short axis and a the longest axis. The demagnetizing factors are IV (in the easy direction) and The demagnetizing fields can then be calculated by Hda = — Na Ms, and Hdb = — Nb Ms. The shape anisotropy field is Hd = (Na — Nb)Ms. Then the switching field Hs = Hd = (Na — Nb)Ms. 

Traditional magnetization reversal has been discussed in the framework of the nucleation theory. The critical fields which cause an equilibrium magnetic state to change were calculated using stability analysis. In addition to the switching field these theories also revealed the reversal mode [22]. The total energy of a magnetic particle may be written in terms of the... 

The equilibrium angle of the magnetization for an external field smaller than the switching field can be easily calculated from Eq. (2) for small y/ [23]... 

The critical angle and the switching field was given by Stoner-Wohlfarth [8]... 

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