Effects of Doping Mn on Nd1.85Ce0.15CuO4 System

Nd1.85Ce0.15Cu1-xMnxO4 samples with doping level up to 20% have been synthesized by solid-state reaction method. The influence of Mn on their normal-state transport, crystal structure, superconductivity and magnetic properties has been investigated. For the samples with x〉0.03, magnetization under zero-field cooling indicates that the magnetic state changes from ferromagnetic to paramagnetic at T≈100 K, which can be explained with the interaction between Mn4＋and Mn3＋. The electrical resistivity p of samples increases with Mn doping. For the samples with doping level lower than 0.20, p initially increases with the decrease of temperature, i.e., dp/dt〈0, and then shows superconductivity transition at ≈20 K. The results suggest the coexistence of superconductivity and ferromagnetic ordering in Mn doped Nd1.85Ce0.15CuO4.