Resistivity and superfluid density measurements on under- and over-doped La$_{2-x}$Sr$_{x}$CuO$_{4}$ films.

We have measured the resistivities and superfluid densities (or, penetration depths, $\lambda )$ of a series of LSCO films with a wide range of Sr concentrations. Films are grown by MBE on LaSrAlO$_{3}$ substrates under nominally identical conditions. Due to substrate mismatch, films are under compression. Resistivities decrease smoothly as Sr concentration increases, and resistive transitions are sharp. T$_{c}$ has a maximum at x = 0.15, while superfluid density 1/$\lambda ^{2}$(0) has a maximum at x $\approx $ 0.18. Interesting features in the T-dependence of 1/$\lambda ^{2}$ will be discussed. Absolute values of resistivity and superfluid density in these films indicates quality comparable to bulk materials. Falloff of superfluid density with overdoping, together with a smooth decrease in resistivity, is consistent with an interpretation in terms of a mesoscopically inhomogeneous superconducting state.