Failure of the empirical OCT law in the Bi2Sr2CuO6+d compound

Authors :: Konstantinovic, Z.
Bras, G. Le
Forget, A.
Colson, D.
Jean, F.
Collin, G.
Li, Z. Z.
Raffy, H.
Ayache, C.
Publication Year :: 2002
Abstract: We have studied the evolution of the thermoelectric power S(T) with oxygen doping of single-layered Bi2Sr2CuO6+d thin films and ceramics in the overall superconducting (Tc, S290K) phase diagram. While the universal relation between the room-temperature thermopower S290K and the critical temperature is found to hold in the strongly overdoped region (d>0.14), a strong violation is observed in the underdoped part of the phase diagram. The observed behaviour is compared with other cuprates and the different scenarios are discussed.<br />7 pages, 5 figures