Hole pockets

Clark et al.n recently discovered another FS related inechanisni in CuPt, different from the above mentioned nesting. In this case, the relevant contribution to the coneentration waves suseeptibility is due to the contemporary presenee of the noble metal-like neck at the L point and the d hole pocket at X. Ifie connecting vector of these Van Hove singularities belongs to the star 1,1,1 and is commensurate with the Lli ordering. In fact, it produces a phase characterised by alt ate hexagonal Cu and Pt planes, in the direction perpendicular to (1,1,1). 

The Fermi surface of WC was proposed based on magnetoresistance and de Haas-van Alphen data taken under high magnetic fields at low temperatures. WC is a semimetal with equal numbers of electron and hole carriers of 1.5 X 1021/cm3. The Fermi surfaces consist of two electron pockets located at the point A and four hole pockets located at the point L, and at the point K or along the T A axis. These results indicate that the spin-orbit interaction is very important in WC. 

FIGURE 6.9 (a) Fermi surfaces for pristine graphite. One electron and two hole pockets are placed at the K... 

Quite complicated porphyrin systems have been constructed with the object of modeling natural systems with biological functions. Some have holes, pockets, and protection for the metal from oxidation by 02. 

EH, ID, 3D (2, 3) semimetal, electron and hole pockets in the Fermi surface... 

Fermi surface for ThC and UC using the relativistic APW method. The calculated results are in good agreement with the de Haas-van Alphen measurements. The UC Fermi surface appears to consist of three hole pockets in the region of the valence C2p states and six electron pockets in the region of the U5/ states. It was shown that UC is a semimetal and contains almost the same number of holes and electrons. 

The calculated band structure and Fermi surface based on the RT crystal structure indicate a 2D hole pocket (Figure 10.6b). The Shubnikov-de Flaas (SdH) measurements of the high-7) salt suggest the existence of a closed Fermi surface of area... 

Anisotropic thermopower effects are observed in the CufNCSlj, Cu(CN)[N(CN)2], and Cu[N(CN)2]Br salts. The thermopower is negative in the direction of the electron-like Eermi surfaces, while it is positive in the direction of the hole pockets. The anisotropic temperature dependence is more quantitatively explained based on the Boltzmann equation by using the calculated band structure with some modification of the bandwidth. The optical spectra in the infrared region of the Cu(NCS)2 and Cu[N(CN)2]Br salts are ascribed to a mixture of intra- and interband transitions (centered around 2200 cm- c, and around 3500 cm b for the Cu(NCS)2 salt). 

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