Institute for Metallic Materials, IFW Dresden, 01171 Dresden, Germany.
Sci Rep. 2013;3:2139. doi: 10.1038/srep02139.
The recently discovered oxypnictide superconductor SmFeAs(O,F) is the most attractive material among the Fe-based superconductors due to its highest transition temperature of 56 K and potential for high-field performance. In order to exploit this new material for superconducting applications, the knowledge and understanding of its electro-magnetic properties are needed. Recent success in fabricating epitaxial SmFeAs(O,F) thin films opens a great opportunity to explore their transport properties. Here we report on a high critical current density of over 10(5) A/cm(2) at 45 T and 4.2 K for both main field orientations, feature favourable for high-field magnet applications. Additionally, by investigating the pinning properties, we observed a dimensional crossover between the superconducting coherence length and the FeAs interlayer distance at 30-40 K, indicative of a possible intrinsic Josephson junction in SmFeAs(O,F) at low temperatures that can be employed in electronics applications such as a terahertz radiation source and a superconducting Qubit.
最近发现的氧磷化物超导体 SmFeAs(O,F) 是铁基超导体中最具吸引力的材料，因为其最高转变温度为 56K，并且具有在高场下表现的潜力。为了将这种新材料应用于超导，需要了解和理解其电磁特性。最近在制备外延 SmFeAs(O,F) 薄膜方面的成功为探索其输运性质提供了巨大的机会。在这里，我们报告了在 45T 和 4.2K 下超过 10(5)A/cm(2)的高临界电流密度，对于两个主要磁场方向都是如此，这是有利于高场磁应用的特性。此外，通过研究钉扎特性，我们在 30-40K 范围内观察到超导相干长度与 FeAs 层间距离之间的维度交叉，这表明在低温下 SmFeAs(O,F) 中可能存在内在的约瑟夫森结，可用于电子学应用，如太赫兹辐射源和超导量子位。
