摘要
We have synthesized polycrystalline samples of Fe1.11(Te1-xSx) and single crystals of Fe1+y(Te0.88S0.12),and characterized their properties.Our results show that the solid solution of S in the Fe1.11Te tetragonal lattice is limited,~10%.We observed superconductivity at ~8 K in both polycrystalline samples and single crystals.Magnetization measurements reveal that the volume fraction is small for this superconducting phase in both polycrystalline samples as-synthesized and single crystals as-grown.It is found that annealing in air enhances the superconducting fraction;the maximum fraction is almost 100% in the single crystals annealed in air at 300°C.We discuss the effect of annealing on superconductivity and transport properties at the normal state in the Fe1+y(Te1-xSx) system in terms of decrease of the excess Fe.
We have synthesized polycrystalline samples of Fe1.11(Te1-xSx) and single crystals of Fe1+y(Te0.88S0.12),and characterized their properties.Our results show that the solid solution of S in the Fe1.11Te tetragonal lattice is limited,~10%.We observed superconductivity at ~8 K in both polycrystalline samples and single crystals.Magnetization measurements reveal that the volume fraction is small for this superconducting phase in both polycrystalline samples as-synthesized and single crystals as-grown.It is found that annealing in air enhances the superconducting fraction;the maximum fraction is almost 100% in the single crystals annealed in air at 300°C.We discuss the effect of annealing on superconductivity and transport properties at the normal state in the Fe1+y(Te1-xSx) system in terms of decrease of the excess Fe.
基金
supported by the National Natural Science Foundation of China (Grant Nos. 10974175 and 10934005)
the National Basic Research Program of China (Grant No. 2009CB929104)
the PCSIRT of the Ministry of Education of China (Grant No. IRT0754)
