Low-temperature synthesis of SmO0.8F0.2FeAs superconductor with Tc = 56.1K Article

cited authors

  • Wang, C; Gao, Z; Wang, L; Qi, Y; Wang, D; Yao, C; Zhang, Z; Ma, Y

fiu authors

abstract

  • We report a systematic study on the effect of sintering temperature on the structural and superconducting properties of nominal SmO0.8F 0.2FeAs fabricated by a simple one-step solid state reaction method. A detailed correlation between the sintering temperature, structure, onset transition temperature (Tc) and critical current density (J c) has been found in all samples of each batch. Most importantly, samples sintered at a low temperature clearly show high Tc, for example the Tc of the samples sintered at 850 °C is even above 53K, and the samples prepared at 1000 °C display the highest Tc of 56.1K reported so far. Furthermore, the samples sintered at 1000 °C also show the highest RRR and the lowest ρ(57K), indicating the low impurity scattering and enhanced carrier density. However, the maximum Jc of 10 510Acm-2 at 5K in the self-field was achieved in the samples sintered at 1100 °C. The dependence of Tc on the a-axis lattice constant indicates that the sintering temperature has a strong influence on the effective substitution level of F for O. This result suggests that annealing at a temperature of ∼ 1000 °C seems much better for obtaining high quality 1111 phase oxypnictides, compared to the commonly used temperatures of around 1200 °C. © 2010 IOP Publishing Ltd.

publication date

  • May 6, 2010

Digital Object Identifier (DOI)

volume

  • 23

issue

  • 5