Magnetic order and electronic phase diagrams of electron-doped copper oxide materials

We report muon spin relaxation and rotation measurements on sintered ceramic samples of Nd_2-x{Ce}ₓCuO_4-y and a large single crystal of Nd₂{CuO}_{4{{-}}y}$. We find an electronic phase diagram that is quite similar to that of hole-doped superconductors such as ${La}_{2{{-}}x}Srₓ{CuO}_{4{{-}}y}$, although the doping of electrons into the system is less efficient in destroying the static moments on the copper ions. Static magnetic order appears in ${Nd}₂CuO_4-y below about 250 K; two spin reorientations are seen at T=75 and 35 K, providing information about the muon site in this material.