FeTe0.6Se0.4 bulk single crystals with high critical current densities under magnetic fields

29th International Symposium on Superconductivity

Tanaka, Y.^1 ; Mizuguchi, Y.^1 ; Miura, O.^1

Dept. of Electrical and Electronic Engineering, Tokyo Metropolitan University, Hachioji

192-0397, Japan^1

关键词: Bulk single crystals;    High critical current densities;    Magnetic field parallel;    Magnetization curves;    Pinning properties;    Remanent magnetization;    Temperature dependence;    Temperature scaling;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/871/1/012064/pdf
DOI  :  10.1088/1742-6596/871/1/012064

来源: IOP

【 摘 要 】

We have fabricated FeTe0.6Se0.4large-size bulk single crystals with high critical current densities (Jc) under magnetic fields. FeTe0.6Se0.4single crystals were prepared by the melting method with two stage heat treatments. The X-ray diffraction (XRD) analysis and the remanent magnetization method showed that the fabricated bulk crystals are intrinsically single crystals from viewpoint of the critical current flow. Temperature dependence of magnetization revealed that low-Tcregion exists inside the crystals. The magnetization curves indicated the typical fishtail type, and the magnetic Jcunder the magnetic field parallel to the c-axis at 4.2 K achieved 0.36 and 0.2 MA / cm2at 0 T and 5 T respectively. From the temperature scaling behavior of flux pinning properties we speculated that low-Tcregions near excess Fe moderately distributed inside the crystals are dominant pinning centers in high fields at low temperatures.