Magnetism in electron-doped copper oxides

We report muon spin relaxation/rotation measurements on sintered powder samples of Nd2−xCexCuO4−y and a large single crystal of Nd2CuO4−y. We find an electronic phase diagram which is quite similar to that of hole-doped superconductors such as La2−xSrxCuO4−y, although the doping of electrons into the system is less efficient in destroying the static moments on the copper spins. Static magnetic order in Nd2CuO4−y appears below about 250 K, and two spin reorientations are seen atT=75 K andT=35 K. Measurements of the magnetic field penetration depth have been unsuccessful due to the rare-earth paramagnetism of these materials.