Wilfong Brandon, Zhou Xiuquan, Zheng Huafei, Babra Navneeth, Brown Craig M, Lynn Jeffrey W, Taddei Keith M, Paglione Johnpierre, Rodriguez Efrain E
Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, USA.
Maryland Quantum Materials Center, University of Maryland, College Park, Maryland 20742, USA.
Phys Rev Mater. 2020 Mar;4(3). doi: 10.1103/PhysRevMaterials.4.034803.
The (Li Fe OH)FeSe superconductor has been suspected of exhibiting long-range magnetic ordering due to Fe substitution in the LiOH layer. However, no direct observation such as magnetic reflection from neutron diffraction has been reported. Here, we use a chemical design strategy to manipulate the doping level of transition metals in the LiOH layer to tune the magnetic properties of the (Li Fe Mn OD)FeSe system. We find Mn doping exclusively replaces Li in the hydroxide layer resulting in enhanced magnetization in the (LiFeMnOD)FeSe superconductor without significantly altering the superconducting behavior as resolved by magnetic susceptibility and electrical/thermal transport measurements. As a result, long-range magnetic ordering was observed below 12 K with neutron diffraction measurements. This work has implications for the design of magnetic superconductors for the fundamental understanding of superconductivity and magnetism in the iron chalcogenide system as well as exploitation as functional materials for next-generation devices.
由于在LiOH层中存在铁替代，（Li Fe OH）FeSe超导体被怀疑表现出长程磁有序。然而，尚未有诸如中子衍射的磁反射等直接观测报道。在此，我们采用一种化学设计策略来操控LiOH层中过渡金属的掺杂水平，以调节（Li Fe Mn OD）FeSe体系的磁性能。我们发现，Mn掺杂仅在氢氧化物层中取代Li，从而导致（LiFeMnOD）FeSe超导体的磁化增强，同时通过磁化率以及电/热输运测量发现超导行为没有显著改变。结果，通过中子衍射测量在12 K以下观察到了长程磁有序。这项工作对于磁超导体的设计具有重要意义，有助于从根本上理解铁硫族化合物体系中的超导性和磁性，以及作为下一代器件的功能材料加以利用。
