We report on the realization of La2-xSrxCuO4 / La2-ySryCuO4 multilayer
s and on a study of the superconducting transitions in magnetic field
parallel and perpendicular to the c-asis. Measuring the activation ene
rgies for thermally activated flux flow, which give information on the
correlation volume involved in flux jumps, allows to make an estimate
of the interdiffusion at the interfaces.