Possible Weak Ferromagnetism in Pr_2-xCe_xCuO₄ Nanocrystals at Normal State

Nano-crystals of Pr_2-xCe_xCuO₄ (PCCO) with x = 0 and 0.15 have been successfully synthesized by chemically dissolved method employing HNO₃ as dissolving agent. The PCCO samples were calcinated at 900 - 1000°C for 5 - 30 h. The PCCO samples were characterized by x-ray diffraction (XRD) and vibrating sample magnetometer (VSM) for investigating the phase formation and crystals size, and for studying the magnetic properties at normal state, respectively. Based on the XRD data, PCCO with x = 0.10 and 0.15 calcinated at temperature of 1000°C for 15 h show no impurity phases with crystal size of around 50 nm using Rietveld analysis. It is shown that the non-superconductive PCCO nano-crystals have very weak ferromagnetic behavior at room temperature. This phenomenon is probably due to magnetic moments rising from oxygen vacancies of the nanocrystals surface.