摘要
Torque measurements were performed on single crystal samples of Ca0.73La0.27(Fe0.96Co0.04)As2 in both the normal and superconducting states.Contributions to the torque signal from the paramagnetism and the vortex lattice were identified.The superconducting anisotropy parameterγwas determined from the reversible part of the vortex contribution based on Kogan's model.It is found thatγ≈7.5 at t=T/Tc=0.85,which is smaller than the result of CaFe0.88Co0.12AsFγ≈15 at t=0.83,but larger than the result of 11 and 122 families,whereγstays in the range of 2-3.The moderate anisotropy of this 112 iron-based superconductor fills the gap between 11,122 families and 1111 families.In addition,we found that theγshows a temperature dependent behavior,i.e.,decreasing with increasing temperature.The fact thatγis not a constant point towards a multiband scenario in this compound.
作者
Ya-Lei Huang
Run Yang
Pei-Gang Li
Hong Xiao
黄亚磊;杨润;李培刚;肖宏(Department of Physics,Zhejiang Sci-Tech University,Hangzhou 310018,China;Center for High Pressure Science and Technology Advanced Research,Beijing 100094,China;Laboratorium für Festkörperphysik,ETH-Zürich,8093,Zürich,Switzerland;Department of Physics,Beijing University of Posts and Telecommunications,Beijing 100876,China)
基金
Project supported by NSAF,China(Grant No.U1530402)
P.G.Li acknowledges the support of the National Natural Science Foundation of China(Grant No.51572241).
