Effect of annealing on superconductivity in Fe1+y(Te1−xSx) system

• Published in: Science China. Physics, mechanics & astronomy Vol. 53; no. 7; pp. 1216 - 1220
• Main Authors: Dong, ChiHeng, Wang, HangDong, Yang, JinHu, Qian, Bin, Chen, Jian, Li, ZuJuan, Yuan, HuiQiu, Fang, MingHu
• Format: Journal Article
• Language: English
• Published: Heidelberg SP Science China Press 01.07.2010; Springer Nature B.V
• Subjects: Annealing; Astronomy; China; Classical and Continuum Physics; Crystal growth; Crystals; Iron; Magnetization; Observations and Techniques; Physics; Physics and Astronomy; Polycrystals; Research Paper; Single crystals; Solid solutions; Superconductivity; Synthesis; Tetragonal lattice; Transport properties; Te; annealing effect; S; Fe-Based superconductors; single crystal; Fe
• ISSN: 1674-7348; 1869-1927
• DOI: 10.1007/s11433-010-4008-z

We have synthesized polycrystalline samples of Fe 1.11 (Te 1− x S x ) and single crystals of Fe 1+ y (Te 0.88 S 0.12 ), and characterized their properties. Our results show that the solid solution of S in the Fe 1.11 Te 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 Fe 1+ y (Te 1− x S x ) system in terms of decrease of the excess Fe.