Effect of F Doping on Fabrication and Superconductivity of SmO1-xFδFeAs Compound

摘要:

研究了F掺杂对铁基超导体SmO0.7F0.3FeAs的制备和性能的影响。利用二次固相反应在1120 ℃保温40 h制备出超导临界转变温度 (Tc) 为56.5 K的SmO0.7F0.3FeAs超导体样品，其临界电流密度Jc为2.4×105 A/cm2 (10 K，0 T)。研究发现，SmO1-xFxFeAs样品的Tc受F含量的强烈影响，晶格参数的变化也是诱导SmO1-xFxFeAs超导体的Tc变化的原因之一。在此基础上详细研究了F元素过掺杂对铁基超导体SmO1-xFδFeAs (δ＞x) 制备参数和性能的影响。F元素过量时，在不降低SmO1-xFδFeAs超导性能的情况下，F元素过掺杂可以一定程度地降低样品制备时的热处理温度和极大地缩短热处理时间。1100 ℃时保温20 h制备的SmO0.7F0.35FeAs和SmO0.7F0.4FeAs样品的Tc分别为56和55 K；其临界电流密度Jc分别为1.9×105和1.7×105 A/cm2 (10 K，0 T)。

Abstract:

We report the effect of fluorine doping on the fabrication and superconductivity of the iron-based arsenic oxide SmO1-xFδFeAs (δ≥x) compound. The fluorine over-doping can greatly reduce the heat treatment temperature and the heat treatment time, meanwhile the superconductivity of the SmO1-xFδFeAs samples does not reduce. The critical transition temperature (Tc) is as high as 56.5 K for the SmO0.7F0.3FeAs sample prepared by the two-step solid state reaction method at 1120 °C for 40 h, the Jc of the sample is 2.4×105 A/cm2 (10 K, 0 T). Tc of the fluorine over-doped SmO0.7F0.35FeAs and SmO0.7F0.4FeAs samples prepared by the two-step solid state reaction method at 1100 °C for 20 h are 56 and 55 K, respectively. Jc of the both samples are 1.9×105 and 1.7×105 A/cm2 (10 K, 0 T), respectively.