Systematic evolution of temperature-dependent resistivity in La2-xSrxCuO4

The in-plane resistivity (ab) of La2-xSrxCuO4 has been studied over a wide temperature (41000 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), ab follows a novel power-law dependence, T1.5, over the entire temperature range up to 1000 K.