Awana, V. P. S. and Pal, Anand and Vajpayee, Arpita and Meena, R. S. and Kishan, H. and Husain, Mushahid and Zeng, R. and Yu, S. and Yamaura, K. and E. , Takayama-Muromachi (2009) Superconductivity in SmFe1−xCoxAsO (x = 0.0–0.30). Journal of Applied Physics, 107 (9). 09E146-1-09E146-3. ISSN 1089-7550

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We report synthesis, structural details, and magnetization of SmFe1−xCoxAsO with x ranging from 0.0 to 0.30. It is found that Co substitutes fully at Fe site in SmFeAsO in an isostructural lattice with slightly compressed cell. The parent compound exhibited known as the spin density wave (SDW) character is below at around 140 K. Successive doping of Co at Fe site suppressed the SDW transition for x = 0.05 and later induced superconductivity for x = 0.10, 0.15, and 0.20, respectively, at 14, 15.5, and 9 K. The lower critical field as seen from magnetization measurements is below 200 Oe. The appearance of bulk superconductivity is established by wide open isothermal magnetization M(H) loops. Superconductivity is not observed for higher content of Co, i.e., x ≥ 0.30. Clearly the Co substitution at Fe site in SmFe1−xCoxAsO diminishes the Fe SDW character, introduces bulk superconductivity for x between 0.10 and 0.20 and finally becomes nonsuperconducting for x above 0.20. The Fe2+ site Co3+ substitution injects mobile electrons to the system and superconductivity appears; however direct substitution introduces simultaneous disorder in superconducting FeAs layer and thus superconductivity disappears for higher content of Co.

Item Type: Article
Subjects: Physics
Depositing User: Ms Neetu Chandra
Date Deposited: 13 Jul 2012 12:52
Last Modified: 13 Jul 2012 12:52

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