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The thermoelectric properties of intermetallic compounds with Ce or Yb ions are explained by the single-impurity Anderson model which takes into account the crystal-field splitting of the 4f groundstate multiplet, and assumes a strong Coulomb repulsion which restricts the number of f electrons or f holes to n f ≤ 1 for Ce and n hole f ≤ 1 for Yb ions. Using the non-crossing approximation and imposing the charge neutrality constraint on the local scattering problem at each temperature and pressure, the excitation spectrum and the transport coefficients of the model are obtained. The thermopower calculated in such a way exhibits all the characteristic features observed in Ce and Yb intermetallics. Calculating the effect of pressure on various characteristic energy scales of the model, we obtain the (T, p) phase diagram which agrees with the experimental data on CeRu2Si2, CeCu2Si2, CePd2Si2, and similar compounds. The evolution of the thermopower and the electrical resistance as a function of temperature, pressure or doping is explained in terms of the crossovers between various fixed points of the model and the redistribution of the single-particle spectral weight within the Fermi window.

The formation energy and local magnetic moment of a series of point defects in CaB6 are computed using a supercell approach within the generalized gradient approximation to density functional theory. It is found that the substitution of Ca by La does not lead to the formation of a local moment, while a neutral B6 vacancy carries a moment of 2.4 Bohr magnetons. A plausible mechanism for the ferromagnetic ordering of these moments is suggested. Since the same broken B-B bonds appear on the preferred (100) cleavage planes of the CaB6 structure, it is argued that internal surfaces in polycrystals as well as external surfaces in general will make a large contribution to the observed magnetization.

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We report on a Raman-scattering investigation of the charge density wave (CDW), quasi-two-dimensional rare-earth tritellurides RTe(3) (R=La, Ce, Pr, Nd, Sm, Gd, and Dy) at ambient pressure, and of LaTe(3) and CeTe(3) under externally applied pressure. The observed phonon peaks can be ascribed to the Raman-active modes for both the undistorted and the distorted lattices in the CDW state by means of a first-principles calculation. The latter also predicts the Kohn anomaly in the phonon dispersion, driving the CDW transition. The integrated intensity of the two most prominent modes scales as a characteristic power of the CDW-gap amplitude upon compressing the lattice, which provides clear evidence for the tight coupling between the CDW condensate and the vibrational modes