Pauli paramagnetic susceptibility

We emphasize that the use of g in these equations may be justified only if /—a, because of the Edwards cancellation theorem (Section 6). We should expect a metal-insulator transition to occur for some value of in the neighbourhood of For several liquid systems there is experimental evidence that the interference term in (52) is absent. Thus for liquid TeTl alloys, with variation of composition and temperature, for a less than the Ioffe-Regel value e2/3hai the conductivity is proportional to the square of the Pauli paramagnetic susceptibility and then to 2. These results are due to Cutler (1977). Warren (1970a, b, 1972a, b) examined... 

With this understanding, it is clear that in a given conduction 0 covalent transformation, a decrease or increase in the number of conduction electrons is an essential feature that should be observable in the transport properties. Assuming that the band structure of TiNi consists of a single positive band, a decrease in the number of conduction (free) electrons in the course of Ms —> As is equivalent to an increase in the number of hole carriers as seen in (c). Consequently, the positive Hall coefficient should decrease and is so observed in (b). Because holes contribute to Pauli paramagnetic susceptibility in precisely the same manner [42] as electrons, the paramagnetic susceptibility, %, is expected to rise and is so observed in (d). An increase in the hole carrier, Nh, would result in an increase in the conductivity (lowering in the resistivity) as... 

PrFe4Sbj2 is likely a metal. Magnetic measurements on polycrystalline samples that were about 90% phase pure indicated ferromagnetic ordering below 5 K with a moment of 1 /i per formula unit. The only other phase detected using X-ray diffraction was FeSb2, which has a weak Pauli paramagnetic susceptibility (Dannebrock et al., 1996). 

Electronic structures of GICs, thus theoretically characterized, are investigated experimentally by means of various techniques, such as x-ray photoemission spectra, ultraviolet photoelectron spectra, electron energy loss spectra, magneto-oscillation, optical reflectance, Raman spectra, Pauli paramagnetic susceptibility, electronic specific heat coefficient, NMR, positron annihilation, etc. Comparisons between theoretical treatments and experimental characterizations will be discussed in the Sections 6.3.2 and 6.3.3 of this chapter for actual GICs. 

Fig. 21. Compositional dependence x of the electronic heat capacity parameter y and Pauli paramagnetic susceptibility x(T) in the metallic region of the systems Lai-xSrxTiOa (circles) and Yi-xCaxTiOa (squares)-, after [96]...

The ESR signal appeared as a line without structures. There was strong coupling between TMTTF radical spins and CigTCNQ radical spins. The temperature dependence of the spin susceptibility was well fitted by the sum of the Curie component and the almost temperature independent part. It is not clear at present whether the latter component is attributed to the Pauli paramagnetic susceptibility [155]. 

The metallic nature of the film was also confirmed by ESR measurements. The results of temperature dependent spin susceptibility are shown in Figure 14.48. The ESR signal of the film was composed of two species and the major component showed Pauli paramagnetic susceptibility due to the conduction electrons on the BEDO-TTF stacks [349,350]. 

To derive the magnetic susceptibility the argument then follows lines which are similar to the treatment of Pauli paramagnetism. Essentially (see Fig. 13), the two populations must have the same pp, and this causes a disequilibrium leading to a net magnetic moment (n+ - n ). The paramagnetic susceptibility is given as ... 

The magnetic susceptibility is also derived from the electron density. There are two contributions (19) the Pauli paramagnetism and the Landau diamagnetism. The former is given by... 

Where strong-correlation fluctuations are present in an itinerant-electron matrix, the magnetic susceptibility may be interpreted as a coexistence of Curie-Weiss and mass-enhanced Pauli paramagnetism. 

Direct confirmation of these conclusions has been obtained by neutron diffraction for CrSb, MnTe, FeS and by susceptibility measurements (see Table VIII). It is significant that the titanium compounds show Pauli paramagnetism, indicative of collective electrons, since 3.15 A < Rtt(c axis) < 3.23 A. This is in agreement with equation 174, which calls for Rc 3.2 A in the more polarizable anion sublattices. 

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