SYSTEMATIC EVOLUTION OF TEMPERATURE-DEPENDENT RESISTIVITY IN LA2-XSRXCUO4

The in-plane resistivity (rho(ab)) of La2-xSrxCuO4 has been studied over a wide temperature (4-1000 K) and composition range (0 < x < 0.35). The much discussed T-linear resistivity is observed only in the narrow composition region associated with optimal superconductivity. In the underdoped range (x < 0.1), we observe first indications of resistivity saturation and analyze the resistivity as indicative of a "small" Fermi surface. In the overdoped range (x > 0.2), rho(ab) follows a novel power-law dependence, rho is-proportional-to T1.5, over the entire temperature range up to 1000 K.