Critical Current Density, Vortex Pinning, and Phase Diagram in the NaCl-Type Superconductors InTe$_{1- x}$Se$_{x}$ ($x = 0$, 0.1, 0.2)
Linchao Yu1†, Song Huang1†, Xiangzhuo Xing1,2*, Xiaolei Yi3, Yan Meng4, Nan Zhou5, Zhixiang Shi6*, and Xiaobing Liu1,2*
1School of Physics and Physical Engineering, Qufu Normal University, Qufu 273165, China 2Advanced Research Institute of Multidisciplinary Sciences, Qufu Normal University, Qufu 273165, China 3College of Physics and Electronic Engineering, Xinyang Normal University, Xinyang 464000, China 4Department of Physics, Jining University, Qufu 273155, China 5Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, China 6School of Physics, Southeast University, Nanjing 211189, China
Abstract：Research of vortex properties in type-II superconductors is of great importance for potential applications and fundamental physics. Here, we present a comprehensive study of the critical current density $J_{\rm c}$, vortex pinning, and phase diagram of NaCl-type InTe$_{1- x}$Se$_{x}$ ($x = 0$, 0.1, 0.2) superconductors synthesized by high-pressure technique. Our studies reveal that the values of $J_{\rm c}$ calculated by the Bean model exceed $10^{4}$ A/cm$^{2}$ in the InTe$_{1- x}$Se$_{x}$ system, signifying good potential for applications. The magnetic hysteresis loops (MHLs) show an asymmetric characteristic at various degrees, which is associated with the surface barrier. Intriguingly, a rare phenomenon in which the second magnetization peak in the MHLs occurs only in the field-descending branch is detected in InTe$_{0.9}$Se$_{0.1}$. Such an anomalous behavior has not been observed before and can be described by considering the respective roles of the surface barrier and bulk pinning in the field-ascending and field-descending branches. By analyzing the pinning force density versus reduced field, the pinning mechanisms are studied in detail in the framework of the Dew-Hughes model. Finally, combining the results of resistivity and magnetization measurements, the vortex phase diagrams are constructed and discussed.
2023, Vol. 40 
