Theory of the thermoelectric power or Seebeck coefficient: The case of phonon scattering for a degenerate free-electron gas

Thermoelectric power studies on Nd1.82−xSrxCe0.18CuOy:x≤0.18 superconductors

“…Further, the electron and phonon spectra are considered to be on the same footing. Durczewski and Ausloos 23 showed that the TEP bump ͑on the positive side͒ grows with characteristic Debye energy or with decreasing electron energy (⑀ s ), and is always negative for ⑀ s Ͼ48 K. These characteristics can be compared with the TEP data of the present work in Fig. 2, curves ͑c͒ and ͑d͒.…”

“…In a recent theoretical approach, model calculations were performed. 23 In that model, the simple free-electron scattering from the spherical Fermi surface by acoustic phonons alone, without the usual electron-phonon mass enhancement effect or Umklapp process, was considered. Sign reversal in the TEP was shown to have resulted from a competitive distribution of charge carriers of the different signs with the carriers being inelastically scattered.…”

Behavior of the thermopower in amorphous materials at the metal-insulator transition

“…8,9 We note that the sign change in S is also observed in metals, high-T c materials, and quasicrystals. [10][11][12] Analytical treatments of metals as a degenerate free-electron gas taking into account inelastic scattering with phonons [13][14][15] as well as numerical considerations incorporating electronic correlations in superconductors 16 have also been shown to generate a sign change in S. But in these systems the sign change occurs at a T value that is 2 orders of magnitude higher than that in disordered systems.…”

“…Hence we have effectively modeled the underlying physical reasons for the sign change-which have been attributed to electron-electron interactions 5 or to the existence of local magnetic moments and their interactions with electrons 8,9 or to inelastic scattering with phonons [13][14][15] -by simply changing the input c (E,T). Regarding a possible test for the existence of such a structured c (E,T), we have shown that the T variation of L 0 is much more sensitive to the bumps than .…”

Coherent Ferromagnetic Precipitate and Anomalies in the Heat Conduction and Thermopower of Mn2-xCrxSb Single Crystals

“…For x > 0.4, apparently the partial properties of the electrons dominate, while for Τ > ΤS those of the holes. Alternatively, changes in the electronic structure through the introduction of a new magnetic Brillouin zone (BZ) [35,36] could occur, in particular introducing hole-like carriers on the one side of the transition and electron-like carriers on the other. However, for the ferrimagnetic-antiferromagnetic transition observed in Mn2-xCrxSb, the BZ changes should not be very large as antiferromagnetism constitutes a special case of ferrimagnetism and as metallic conduction persists through the transition.…”