Magnetic-field effect on static antiferromagnetic order above the upper critical field in Nd1.85Ce0.15CuO4

We use neutron scattering to study the effect of a c-axis-aligned magnetic field on superconducting Nd1.85Ce0.15CuO4 for fields above its upper critical field. We also determine the effect of such a field on the cubic impurity phase (Nd,Ce)(2)O-3. By comparing these data with previous field-induced results on other electron-doped materials, we conclude that while the impurity phase is responsible for scattering at (1/2,0,0), application of a magnetic field does induce a quantum phase transition from the superconducting to an antiferromagnetic state in electron-doped high-T-c superconductors.