The most typical peculiarities of the charge transport phenomena in bismuth monocrystals complexly doped with donor-acceptor impurities (Sn-Te, Pb-Te, Pb-Se) are considered. The main attention is paid to "quasi-compensated" crystals (n » p). It is shown that the impurity states in bismuth significantly influence the energy spectrum of the charge carriers.

The non-equilibrium temperature distributions in one- and two-temperature semiconductor models with absorption on the surface of rectangular thermal flow pulse of arbitrary duration have been determined with analytic precision. In one-temperature model local electron and phonon temperatures coincide, relaxation process is characterized by the uniform relaxation time depending on the sample thermal diffusivity and its length. In two-temperature model the electron and phonon temperatures in the general case are different. The case of nondegenerate semiconductors was examined characterized by a considerable excess of the phonon thermal conductivity k_p over the electron k_e, and high electron thermal diffusivity D_e as compared to phonon D_p. It was shown that in the zero approximation according to parameters k_e/k_p and D_p/D_c the phonon subsystem is not thermally excited and its temperature is equal to ambient temperature. In contrast to one-temperature model, this model is characterized by two characteristic relaxation times, the time of nonequilibrium electron thermal process relaxation into the external thermostat depending on electron thermal diffusivity and sample length, as well as the time of energy relaxation into phonon subsystem, i.e. the time of energy relaxation at electron-phonon interaction. It was noted that each of these relaxation times can be dominant depending on the sample length. Transient processes for arbitrary relations of absorbed thermal pulse duration and characteristic relaxation times have been analysed. Thermoelectric responses to these processes have been calculated and the possibility of recovering a number of thermal physical parameters from the experimental curves of transient thermoelectric processes has been indicated.

We have measured the resistivity r(T) and the thermoelectric power S(T) in the metallic glass system Ti-Cu-Co. The S(T) is not linear over the entire measured temperature range for any of the samples. We find that as r increases, a becomes negative, and S increases and becomes positive. These results agree with the Mooiji correlation and with a correlation of S>0 with high r and S<0 with low r, which is also seen in many nonmagnetic metallic glasses. We compare our results with several theories for electron scattering.