Isotropic negative magnetoresistance in La2-xSrxCuO4+y

Measurements are reported of the magnetoresistance of thoroughly characterized single crystals of La{sub 2{minus}{ital x}}Sr{sub {ital x}}CuO{sub 4+{ital y}} with 0.02{le}{ital x}{le}0.1. Above the superconducting critical temperature, the conductance of the CuO{sub 2} layers increases logarithmically with temperature at low {ital T}. However, the magnetoresistance is isotropic and negative, inconsistent with coherent backscattering or conventional interaction effects, suggesting that spin scattering limits the conductance.