Upper critical field, critical current density and thermally activated flux flow in fluorine doped CeFeAsO superconductors

作者：Shahbazi M; Wang X L^*; Shekhar C; Srivastava O N; Dou S X

来源：Superconductor Science and Technology, 2010, 23(10): 105008.

DOI：10.1088/0953-2048/23/10/105008

We report our studies on the crystal structures, morphologies, and superconductivity in CeO1-xFxFeAs compounds which were fabricated by solid state reaction. The crystal structures were refined using Rietveld refinement. Superconducting properties such as critical temperature (T-c), critical current density (J(c)), and upper critical field (H-c2) were determined using magneto-transport and magnetic measurement over a wide range of temperature below T-c, and in magnetic fields up to 13 T. J(c) is 2 x 10(3) A cm(-2) for the x = 0.1 sample. However, the J(c) exhibited a weak dependence on magnetic field for B > 1 T and T = 5 and 10 K. A peak effect in the J(c) as a function of field was observed at 20 K in the x = 0.1 sample. We estimate H-c2(ab) of 185 T for CeO0.9F0.1FeAs compound. The broadening of the superconducting transition near T-c with increasing field can be well understood using the thermal activated flux flow model. The pinning potential scales as U-0/K-B alpha B-n with n = 0.2 for B < 3 T and n = 0.71 for B > 3 T in the x = 0.1 sample.

• 出版日期2010-10