Temperature coefficient magnetization

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). 

In some cases they were able to quench deton completely by an applied magnetic field, and in one experiment they determined the temperature coefficient of voltage required to quench detonation in 20 mol % acetylene and 80% air to be positive. Malinovskii Lavrov stated that negative charges actively propagate the deton wave in 25/75 mol % acetylene... 

The crystal structure of cadmium rhenium(V) oxide, as determined by single-crystal technique,1 is of the face-centered cubic pyrochlore type (a = 10.219 A.). The only positional parameter for the 48 (/) oxygens is x = 0.309 0.007 when rhenium is at the origin. The density, determined pycnometrically, is 8.82 0.03 g./cc., compared with the theoretical value of 8.83 g./cc. for Z = 8. The resistivity between 4.2 K and room temperature is very low (10-3-10-4 J2-cm.) and has a positive temperature coefficient. Over the same temperature range the magnetic susceptibility is low and temperature-independent. These properties indicate that cadmium rhenium(V) oxide exhibits metallic conductivity. 

The magnetic susceptibility of water has frequently been determined, the value for K X10 at 20° C. being 0-7029 with a temperature coefficient... 

Only the two first methods allow measurement of the temperature coefficient of the surface energy. The maximum bubble pressure technique is well-adapted for metals with low and intermediate melting points and specially for oxidizable metals, while the sessile drop technique has been applied with success to measure ctlv values up to 1500°C. The drop weight method is particularly useful for very high melting-point metals because it avoids liquid contact with container materials. This is also true for the recently developed levitation drop technique that analyses the oscillation spectrum of a magnetically levitated droplet. 

D2O has the further advantage that the solvent isotope effect on mutarotation is usually greater than that on glycosidase catalysis. The temperature coefficient of most enzymes, moreover, is less than that of mutarotation, so it is often advantageous to cool the sample. Finally, the more powerful the magnet, the fewer the FIDs and hence the shorter the time that is required to obtain a good spectrum. Tours de force of NMR-based glycosidase stereochemistry... 

The slightly reduced values of the room-temperature anisotropy fields when relatively small amounts of Fe in R2Fe14B are replaced by Co (see fig. 19) are not the only reason why Co substitution does not lead to improved hard magnetic properties. This is true for the temperature coefficient of the coercive force in particular. A probable reason for this is that not only JIA itself but also its temperature dependence becomes less favourable upon Co substitution. This may be inferred already from a comparison of the temperature dependences of HA in the pure ternaries Nd2Fe14B and Nd2Co17B shown in fig. 21, where it can be seen that the slope of the HA(T) curve for the latter compound around room temperature is much steeper than that of the former. In fact, the HA(T) curve in Nd2Co14B tends to approach the horizontal axis at a temperature of about 540 K, which is still far below the corresponding Curie temperature (Tc = 1007 K). The most obvious... 

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