Different behavior of upper critical field in Fe1-xSe single crystals  

作　　者：Shunli Ni Wei Hu Peipei Shen Zhongxu Wei Shaobo Liu Dong Li Jie Yuan Li Yu Kui Jin Fang Zhou Xiaoli Dong Zhongxian Zhao 倪顺利;胡卫;沈沛沛;魏忠旭;刘少博;李栋;袁洁;俞理;金魁;周放;董晓莉;赵忠贤(Beijing National Laboratory for Condensed Matter Physics and Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China;School of Physical Sciences,University of Chinese Academy of Sciences,Beijing 100049,China;Key Laboratory for Vacuum Physics,University of Chinese Academy of Sciences,Beijing 100049,China;Songshan Lake Materials Laboratory,Dongguan 523808,China)

机构地区：[1]Beijing National Laboratory for Condensed Matter Physics and Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China [2]School of Physical Sciences,University of Chinese Academy of Sciences,Beijing 100049,China [3]Key Laboratory for Vacuum Physics,University of Chinese Academy of Sciences,Beijing 100049,China [4]Songshan Lake Materials Laboratory,Dongguan 523808,China

出　　处：《Chinese Physics B》2019年第12期48-51,共4页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Grant Nos.11888101 and 11834016);the National Key Research and Development Program of China(Grant Nos.2017YFA0303003 and 2016YFA0300300);the Strategic Priority Research Program and Key Research Program of Frontier Sciences of the Chinese Academy of Sciences(Grant Nos.QYZDY-SSW-SLH001 and XDB25000000)

摘　　要：The temperature dependences of upper critical field(Hc2) for a series of iron-deficient Fe1-xSe single crystals are obtained from the measurements of in-plane resistivity in magnetic fields up to 9 T and perpendicular to the ab plane. For the samples with lower superconducting transition temperature Tc(< 7.2 K), the temperature dependence of Hc2 is appropriately described by an effective two-band model. For the samples with higher Tc( 7.2 K), the temperature dependence can also be fitted by a single-band Werthamer–Helfand–Hohenberg formula, besides the two-band model. Such a Tc-dependent change in Hc2(T) behavior is discussed in connection with recent related experimental results, showing an inherent link between the changes of intrinsic superconducting and normal state properties in the Fe Se system.The temperature dependences of upper critical field(Hc2) for a series of iron-deficient Fe1-xSe single crystals are obtained from the measurements of in-plane resistivity in magnetic fields up to 9 T and perpendicular to the ab plane. For the samples with lower superconducting transition temperature Tc（< 7.2 K）, the temperature dependence of Hc2 is appropriately described by an effective two-band model. For the samples with higher Tc（ 7.2 K）, the temperature dependence can also be fitted by a single-band Werthamer–Helfand–Hohenberg formula, besides the two-band model. Such a Tc-dependent change in Hc2（T） behavior is discussed in connection with recent related experimental results, showing an inherent link between the changes of intrinsic superconducting and normal state properties in the Fe Se system.

关 键 词：iron-deficient Fe1-xSe superconductors upper critical field MAGNETORESISTIVITY 

分 类 号：TG1[金属学及工艺—金属学]