Coexistence of Superconductivity and Ferromagnetism in Dilute Co-doped $La_{1.89} Ce_{0.11} Cu O_{4\pm\d}$ System
arXiv:cond-mat/0608320 · doi:10.1103/PhysRevB.74.094518
Abstract
Thin films of the optimally electron-doped -phase superconductor LaCeCuO$_{4\pm \d}$ are investigated by dilute Co doping, formed as LaCe(CuCo)O$_{4\pm\d}$ (LCCCO) with = 0.01 -- 0.05. The following results are obtained for the first time: for the whole dilute Co doping range, LCCCO thin films show long-range ferromagnetic ordering at the temperature range from 5 K to 300 K, which is likely due to the RKKY interaction; in the very dilute Co doping, = 0.01 and 0.02, the superconductivity is maitained, the system shows the coexistence of superconductivity and ferromagnetism in the CuO plane. This may be based on the nature of the charge carriers in electron-doped high- cuprate superconductors.
5 pages, 4 figures, accepted for publication in Physical Review B