Publication Details

Wang, X, Ghorbani, SR, Lee, S, Dou, SX, Lin, C, Johansen, T, Muller, K, Cheng, ZX, Peleckis, G, Shabazi, M, Qviller, A, Yurchenko, VV, Sun, G, & Sun, D (2010), Very strong intrinsic flux pinning and vortex avalanches in (Ba, K)Fe2As2 superconducting single crystals, Physical Review B (Condensed Matter and Materials Physics), 82(2), pp. 024525-1-024525-5.


We report that the (Ba,K)Fe2As2 crystal with Tc=32 K shows a pinning potential, U0, as high as 104 K, with U0 showing very little field dependence. The (Ba,K)Fe2As2 single crystals become isotropic at low temperatures and high magnetic fields, resulting in a very rigid vortex lattice, even in fields very close to Hc2. The isotropic rigid vortices observed in the two-dimensional (2D) (Ba,K)Fe2As2 distinguish this compound from 2D high-Tc cuprate superconductors with 2D vortices. The vortex avalanches were also observed at low temperatures in the (Ba,K)Fe2As2 crystal. It is proposed that it is the K substitution that induces both almost isotropic superconductivity and the very strong intrinsic pinning in the (Ba,K)Fe2As2 crystal.

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