Thermopower in Bi2Sr2Ca(Cu1-xFex)(2)O-y (x=0-0.1) with various oxygen content

Systematic study of the normal-state thermopower, S, for Bi2Sr2Ca(Cu1-xFex)(2)O-y ceramic samples has been carried out. The doping by Fe leads to a decrease of the critical temperature and an increase of the thermopower value for both investigated series (as-sintered and oxygen-reduced samples) while these effects are stronger in the second case. For a low doping level, the thermopower shows a linear temperature dependence that is typical for Bi-based HTSC. As doping level increases, the S(T) dependence becomes weaker and has a well-pronounced maximum around T=150-200 K like non-stoichiometric Y-123. The results are discussed within a band spectrum model.