Measurements of the Hall Effect and Resistivity in La$_{\rm 2-x}$Sr$_{\rm x}$CuO$_{\rm 4+\delta}$ with Ultrafine Stoichiometry Resolution, $\delta x$~$\sim$~2.5~$\times$~10$^{\rm -4}$

Recent reports of sharp changes of transport properties with small variations of stoichiometry in cuprate superconductors have motivated us to look for similar behavior in optimally- and over-doped La$_{\rm 2-x}$Sr$_{\rm x}$CuO$_{\rm 4+\delta}$, using a recently completed system for creating and measuring samples with ultrafine stoichiometry resolution. The data are from MBE films grown with a linear stoichiometry gradient and were taken with a characterization system that can measure both the Hall effect and resistivity simultaneously at 31 different locations on the film. We will show new data for $x$ ranging from 0.15 to 0.30.