Unusual Normal and Superconducting State Properties Observed in Hydrothermal Fe1-δSe Flakes

• 作者: Shaobo Liu Sheng Ma Zhaosheng Wang Wei Hu Zian Li Qimei Liang Hong Wang Yuhang Zhang Zouyouwei Lu Jie Yuan Kui Jin Jian-Qi Li Li Pi Li Yu Fang Zhou Xiaoli Dong Zhongxian Zhao
• 来源期刊: 中国物理快报（英文版）
• 年，卷（期）: 2021,（5）
• 所属期刊栏目: CONDENSED MATTER:ELECTRONIC STRUCTURE,ELECTRICAL,MAGNETIC,AND OPTICAL PROPERTIES
• 页码范围: 121-125
• 页数: 5页
• 语种: 英文
• DOI: 10.1088/0256-307X/38/5/057401

摘要

The electronic and superconducting properties of Fe1-δSe single-crystal flakes grown hydrothermally are studied by the transport measurements under zero and high magnetic fields up to 38.5 T.The results contrast sharply with those previously reported for nematically ordered FeSe by chemical-vapor-transport (CVT) growth.No signature of the electronic nematicity,but an evident metal-to-nonmetal crossover with increasing temperature,is detected in the normal state of the present hydrothermal samples.Interestingly,a higher superconducting critical temperature Tc of 13.2 K is observed compared to a suppressed Tc of 9 K in the presence of the nematicity in the CVT FeSe.Moreover,the upper critical field in the zero-temperature limit is found to be isotropic with respect to the field direction and to reach a higher value of ～42 T,which breaks the Pauli limit by a factor of 1.8.