Variation in the In-Plane Penetration Depth lambda(ab) as a Function of Doping in La(2-x)Sr(x)CuO(4+/-delta) Thin Films on SrTiO(3): Implications for the Overdoped State

Normal-state properties, such as the resistivity rho(ab) and the Hall coefficient R(H), structural properties, such as the c-axis and in-plane lattice parameters, and superconductive properties, such as the critical temperature Tc, the penetration depth lambda(ab) and the thermal activation energy for flux flow Delta U, are reported for c-axis
La(2-x)Sr(x)CuO(4+/-delta) films. These parameters have been measured as a function of doping in the range from heavily underdoped to heavily overdoped. The structural data indicate a 0.3% compression of the c-axis parameter and a corresponding 0.3% expansion of the in-plane lattice parameters as compared to bulk values, which explains the overall reduced critical temperature of these thin films. As the dopant content is increased, maximum values for Tc, Delta U and lambda(ab)**-1 are observed close to optimum doping, while R(H) and rho(ab) decrease monotonically.