Low temperature preparation and superconductivity of F-doped SmFeAsO

✍ Scribed by Y.L. Chen; Y.J. Cui; C.H. Cheng; Y. Yang; L. Wang; Y.C. Li; Y. Zhang; Y. Zhao

• Book ID: 104084583
• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 806 KB
• Volume: 470
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/j.physc.2010.05.017

✦ Synopsis

SmFeAsO 1Àx F x a b s t r a c t A low temperature (1100 °C) process of preparing F-doped SmFeAsO samples has been developed using SmF 3 with nanometer scale as the source of fluorine. A series of the SmFeAsO 1Àx F x (x = 0, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3) samples have been prepared using the present method. Compared with previous reports, the present SmF 3 is more effective to introduce F into SmFeAsO system in which a transition temperature of 39 K can be observed when x = 0.05. The superconductivity is definitely enhanced with the increasing F-doping level. All the samples presented to be layered structure and the crystal particle size is about three times larger with sintering time increasing from 36 h to 48 h. Except for the nanometer scale of SmF 3 , the flux effect of SmF 3 is recognized to be another reason for the decrease of the sintering temperature. Further more, a relatively large amount of SmF 3 was also employed in the raw materials to introduce excessive F and this has induced higher T c (55 K) in SmFeAsO 0.8 F 0.2+d system.