Saturation magnetization temperature dependence

The hysteresis loops of most BC/Fe O NPs has been measure in several studies [209, 259, 260, 265], pointing to a wide range of saturated magnetization values depending on the Fe O NPs content and in the temperature. However, it is worth mentioning that... 

The saturation magnetization, J), is the (maximum) magnetic moment per unit of volume. It is easily derived from the spia configuration of the sublattices eight ionic moments and, hence, 40 ]1 per unit cell, which corresponds to = 668 mT at 0 K. This was the first experimental evidence for the Gorter model (66). The temperature dependence of J) (Fig. 7) is remarkable the — T curve is much less rounded than the usual BdUouia function (4). This results ia a relatively low J) value at RT (Table 2) and a relatively high (—0.2%/° C) temperature coefficient of J). By means of Mitssbauer spectroscopy, the temperature dependence of the separate sublattice contributions has been determined (68). It appears that the 12k sublattice is responsible for the unusual temperature dependence of the overall J). 

Fig. 9. Temperature dependences of the saturation magnetization AF, the coercivity FF and the Kerr rotation 9j for a 50-nm GdQ 24 0 oi o 75...

In Fig.. I we present the temperature dependence of the conductance for one of the CNTs, measured by means of a three-probe technique, in respectively zero magnetic field, 7 T and 14 T. The zero-field results showed a logarithmic decrease of the conductance at higher temperature, followed by a saturation of the conductance at very low temperature. At zero magnetic field the saturation occurs at a critical temperature, = 0.2 K, which shifts to higher temperatures in the presence of a magnetic field. 

Mo(V) paramagnetic species is also an argument to exclude an interaction between the Mo site and Fe-S center I. These studies were further complemented by detailed study of the observable splitting and its temperature dependence, EPR saturation, and the effect of differential reduction of the Fe-S centers. A magnetic interaction was also seen in xanthine oxidase, between various Mo(V) EPR species and one of the Fe-S centers. A study on the... 

Fig. II. (a) Temperature dependence of the magnetization for 200-nm thick Ga, MnrAs with x =0.053. The magnetic field is applied perpendicular to the sample surface (hard axis). The inset shows the temperature dependence of the remanent magnetization (0 T) and the magnetization at 1 T in a field parallel to the film surface, (b) Temperature dependence of the saturation magnetization determined from the data shown in (a) by using ArTott plots (closed circles). Open circles show inverse magnetic susceptibility and the Curie-Weiss fit is depicted by the solid straight line (Ohno and Matsukura 2001).

Although we have considered only the zero temperature case, at finite temperatures T -C SE our result should still hold. In the case SE T Aq we expect that the dependence on the applied magnetic filed will be saturated by temperature such that one should substitute SE —> T in (93), the coefficient / for this case requires a more advanced study. 

The temperature dependence of the individual linewidth, eq. (21), is rather complicated. At very low temperatures the Langevin function in this equation becomes saturated for the majority of the nanoparticles, so that the main mechanism of this dependence is the thermal modulation of the magnetic anisotropy energy. Indeed, one can see from figure 8 (bottom) that the Ar temperature dependence provides a good estimate of the experimental low-temperature linewidth. As the damping factor linearly depends on the linewidth, it follows the same temperature dependence [11],... 

Figure 3. Temperature dependence of the magnetoelastic stress parameter Br 2 oi La0 67Ca0i33MnO3 film. The continuous line is a fit by the Callen and Callen law [5Y-Br,2(T) = 5r 2(0)/5/2L 1[m(T)], where m(T)- reduced saturation magnetization and...

W = initial weight or dry weight, depending upon whether 9 the per cent initial or, the per cent dry weight were desired and the factor of 218 is the room-temperature saturation-magnetization of iron. 

Exact forms of a distance-dependent /( are not available. Before going into details, Table 5.4 lists the saturation magnetization Ms, the effective number of Bohr magnetons per atom, and the ferromagnetic Curie temperature Tc for selected ferromagnets. 

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