Yu Jia, Liu Tong, Pan Bo-Jin, Ruan Bin-Bin, Wang Xiao-Chuan, Mu Qing-Ge, Zhao Kang, Chen Gen-Fu, Ren Zhi-An
Institute of Physics and Beijing National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100190, China.
Institute of Physics and Beijing National Laboratory for Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100190, China; Collaborative Innovation Center of Quantum Matter, Beijing 100190, China; School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100039, China.
Sci Bull (Beijing). 2017 Feb 15;62(3):218-221. doi: 10.1016/j.scib.2016.12.015. Epub 2017 Jan 17.
We report the discovery and characterization of a novel 112-type iron pnictide EuFeAs, with La-doping induced superconductivity in a series of EuLaFeAs. The polycrystalline samples were synthesized through solid state reaction method only within a very narrow temperature window around 1073K. Small single crystals were also grown from a flux method with the size about 100μm. The crystal structure was identified by single crystal X-ray diffraction analysis as a monoclinic structure with space group of P2/m. From resistivity and magnetic susceptibility measurements, we found that the parent compound EuFeAs shows distinct anomalies probably due to the Fe related antiferromagnetic/structural phase transition near 110K and the Eu related antiferromagnetic phase transition near 40K. La-doping suppressed both phase transitions to lower temperatures and induced superconducting transitions with a T∼11K for EuLaFeAs.
我们报道了一种新型112型铁基氮化物EuFeAs的发现与表征，以及在一系列EuLaFeAs中La掺杂诱导的超导性。多晶样品仅通过固态反应法在1073K左右非常窄的温度窗口内合成。还通过助熔剂法生长出尺寸约为100μm的小单晶。通过单晶X射线衍射分析确定晶体结构为空间群为P2/m的单斜结构。从电阻率和磁化率测量中，我们发现母体化合物EuFeAs表现出明显的异常，这可能是由于在110K附近与Fe相关的反铁磁/结构相变以及在40K附近与Eu相关的反铁磁相变。La掺杂将两个相变都抑制到更低温度，并在EuLaFeAs中诱导出超导转变，其超导转变温度T约为11K。
