Brillouin zone effects on the critical temperature of superconductors and some related normal metal properties

Anisotropy of the normal state properties of the superconducting Co1?x Ni x Zr2 system

“…This result implies that the thermoelectric power has a negative hump at least below 0.40D, where the Debye temperature 0D lies between 240 and 250 K for the compositional range examined. 5 Phonon drag effects can produce positive thermoelectric power peaks in isotropic metals at temperatures in the range (0.1--0.2)0D and negative ones in anisotropic metals, t° Highly anisotropic at low temperatures, the polyvalent metals Mg, Co, and Zn show positive or negative thermoelectric power maxima attributable to the phonon drag contribution due to small portions of the Fermi surface. 11 However, it has also been found that second-order, intrinsic two-phonon processes 12 or higher order electronphonon processes 13 may give a significant contribution to the electron diffusion thermoelectric power at low temperatures.…”