Analysis of peak effect in the critical current density and flux pinning properties in iron based superconducting Ca10(Pt4As8)(Fe2?xPtxAs2)5 single crystal

[摘要] We present the magnetic properties of the iron based superconducting Ca10(Pt4As8)(Fe2-xPtxAs2)5(x =0.01) single crystal as a function of field and time. The single crystals were grown by Bridgman method and showed Tcof 32 K. The results show that the well-known secondary peak effect becomes prominent in certain temperature range in the field dependent magnetic hysteresis. Moreover, the maximum of pinning force density Fmaxversus Hmaxfollows a scaling law Fp,max49.5Hmax3/2indicating the single type pinning mechanism is involved in the sample within our measured temperature range. The time dependence of the magnetization indicates thermally activated flux motion and the relaxation rate reveals a plateau in the temperature region where secondary peak effect is more prominent after that a sudden increase is observed. We found that the magnetization dependence of activation energy U obtained by Maley's method follows a power law in low temperature region with exponent μ 0.15 which is in good agreement with collective pinning theory.

[发布机构] Department of Emerging Materials Science, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu; 711-873, Korea, Republic of^1;DGIST-LBNL Joint Research Center, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu; 711-873, Korea, Republic of^2;Center for X-ray Optics, Lawrence Berkeley National Laboratory (LBNL), Berkeley; CA; 94720, United States^3;Department of Physics, Pusan National University, Busan; 609-735, Korea, Republic of^4

[关键词] Collective pinning theory;Low temperature regions;Magnetization dependence;Measured temperatures;Pinning force density;Pinning properties;Temperature regions;Thermally activated flux motion