Curie concentration dependence

Fig. 25. Concentration dependence of the Curie temperature in Nd2(Fe1 tMI)14B for various types of...

For a range of related materials the concentration dependence of the magnetization M, Curie temperature Tc and initial susceptibility xo takes the form... 

In conclusion, s.s. dependence on temperature, for gamma irradiated PP is cuiomalous around Tq, due to an a-nomaly in oxygen diffusion across the glassy transition region. However, as RO concentration depends on time and temperature and because we have no reason to suppose a particular type of spin susceptibility dependence on temperature, is not possible to convert s.s. dependence on temperature in the dependence of RO concentration on temperature. For usual Curie or Curie-Weiss spin susceptibility dependence on temperature, the anomaly reported by us is a true anomaly in the number of RO, centers. 

The pseudobinary compounds Gd(Ali-j,CUjj)2 are used to study the effect of the variation of the conduction electron concentration on the ordering temperature and the resistivity (Sakurai et al., 1977). The p vs. T curves of several samples of this cubic pseudobinary system are given in fig. 25. The concentration dependence of Pspd and of the Curie temperature are shown in fig. 26. Pspiix) and Tc(x) vary in a similar manner with increasing Cu concentration. The change in these two quantities can be explained by the variation of the exchange integral with conduction electron concentration (Sakurai et al., 1977). 

Fig. 39. Concentration dependence of the Curie temperatures in various amorphous Gd-alloys (after Buschow and Van der Kraan, 1981).

The number of electron paramagnetic resonance (EPR) investigations made on amorphous alloys is rather limited. Bates et al. (1971) investigated amorphous Gd, j.Agj. alloys prepared by dropping a powdered-mixture of Gd and Ag on to a molybdenum filament having a temperature of 2000°C. Condensation of the vapour was allowed to take place on substrates either kept at room temperature or cooled with liquid helium or liquid nitrogen. For various compositions the authors studied the temperature dependence of the linewidth. Curie temperatures were estimated from the position of the minima occurring in the linewidth-versus-temperature plots. Bates et al. found that the concentration dependence of the Curie temperature in Gd, sharp minimum (7 = 45 K) near x — 0.10 in alloys deposited on... 

In normal metals the Pauli susceptibility is constant with temperature, but in normal metals we are dealing with bandwidths in the order of eV and the density of states is practically constant near the Fermi level. In heavy fermions the density of states changes very rapidly with energy which produces drastic effects in the temperature dependence of the susceptibility. The formulae which we adopt for the derivation of the Pauli susceptibility are eqs. (17-19) where the int ral in eq. (18) is the well known expression of the Pauli magnetization. When a peak in the density of states occurs at the Fermi level, this term shows a Curie-Weiss dependence with temperature and the susceptibility decreases more rapidly as the peak is enhanced and the bandwidth is reduced. We can also explain the susceptibility of heavy fermions in different, simpler terms. With Eji = and the carrier concentration N being... 

Fig. 14.113. Concentration dependence of the saturation moment and Curie temperature of (Ho, Y)Coj and (Ho, Y)(Feo,iCoo.9)2 (Steiner and Ortbauer, 1975). Line A shows the expected contribution to

Fig. 3a. B-Fe-P. Concentration dependence of the Curie point for Fe3P and Xi solid solutions...

The locations of the lielriangle and binodal curies in the phase diagram depend on the moleeulai structures of the amphiphile and oil. on Ihe concentration of cosurfactant and/or electrolyte if either of these components is added, and on the temperature (and, especially for compressible oils, on the pressure I. 

Figure 4. The dependence of Curie temperature on the hydrogen concentration for Er2Fei4BHx.

The amount of radon that enters a building depends on the geology of the zone, the concentration of the gas, the pathways into the building and its ventilation rate. The US EPA recommended limit indoor radon concentration is 4 pico Curies/L. 

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