Mn doping effect on superconductivity and magnetic properties of Nd1.85Ce0.15CuO4 system

Abstract

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 ρ of samples increases with Mn doping. For the samples with doping level lower than 0.20, ρ initially increases with the decrease of temperature, i.e., dρ/dt<0, and then shows superconductivity transition at T≈20 K. The results suggest the coexistence of superconductivity and ferromagnetic ordering in Mn doped Nd1.85Ce0.15CuO4.