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

Abstract

We report a systematic study on the effect of sintering temperature on the structural and superconducting properties of nominal SmO0.8F0.2FeAs fabricated by simple one-step solid state reaction method. A detailed correlation between the sintering temperature, structure, onset transition temperature (Tc) and critical current density (Jc) has been found in all samples of each batch. Most importantly, samples sintered at a low temperature clearly shows high Tc, for example the Tc of the samples sintered at 850C is even above 53 K, and the samples prepared at 1000C display the highest Tc of 56.1 K reported so far. Furthermore, the samples sintered at 1000C also show the highest RRR and the lowest resistivity(57K), indicating the low impurity scattering and enhanced carrier density. However, the maximum Jc of 10510 A/cm^2 at 5 K in self field was achieved in the samples sintered at 1100oC. The dependence of Tc on a-axis lattice constant indicates that the sintering temperature has strong influence on the effective substitution level of F for O. This result suggests that annealing at a temperature of ~1000C seems much better for obtaining high quality 1111 phase oxypnictides, compared to commonly used temperatures of around 1200C.

17 pages, 5 figures

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• Structural and critical current properties in polycrystalline SmO1-xFxFeAs

Cited by in corpus (10)

• Development of Powder-in-Tube Processed Iron Pnictide Wires and Tapes
• Transition Temperature and Upper Critical Field in SmFeAsO1-xFx Synthesized at Low Heating Temperatures
• The effect of exceptionally high fluorine doping on the anisotropy of single crystalline SmFeAsO1-xFx
• Electronic structure of BaNi${}_2$As${}_2$
• Controlling Factors of Tc-Dome Structure in 1111-Type Iron Arsenide Superconductors
• Density effect on critical current density and flux pinning properties of polycrystalline SmFeAsO1-xFx superconductor
• α-FeAs-free SmFeAsO1-xFx by low temperature sintering with slow cooling
• Antimony Doping Effect on the Superconducting Properties of SmFeAs(O,F)
• Effects of the sintering atmosphere on the superconductivity of SmFeAsO1-xFx compounds
• Fluorine-substitution-dependent phase diagram and superconducting properties of Sm-based oxypnictides synthesized by a high-pressure growth technique