FeSe晶体生长和超导性能研究

Large FeSe single crystal growth and its superconducting property

摘要:

层状FeSe是一种重要的超导材料,但生长大尺寸的晶体使得深入探究其超导机理变得困难。在本研究中,我们利用了简单的KCl熔盐法生长晶体,通过在熔剂内部控制温度梯度,生长得到了尺寸为7×2×2mm_³的大晶体。通过X射线衍射分析,确定晶体为基面为(101)面的四方β-FeSe超导相。磁性测量表明晶体在9k时发生了超导转变；四探针法测量表明伴随着较宽的转变温度范围,晶体在10K时电阻值降为零,起始转变温度为15K。本研究为制备大尺寸FeSe单晶提供了一种便利简捷的方法,对于FeSe基超导体的研究具有广阔的应用前景。

Abstract:

Layered FeSe has become one important superconducting material, but the major challenge in the growth of large crystal makes it difficult to further clarify the underlying superconducting mechanism. In this research, large crystals with a typical size of 7×2×2 mm3 are obtained simply by using KCl flux with a controlled temperature gradient inside the flux. Superconducting tetragonal β-FeSe phase with the basal plane of (101) face is identified by X-ray diffraction analysis. The super large crystals show outstanding superconducting performance with transition happened at 9 K according to the DC magnetization measurements and broad resistive transition to zero resistance at 10 K with an onset temperature of 15 K. Our work has provided a convenient method to synthesis large FeSe single crystals which is promising in investigations of FeSe-based superconductors.