Abstract:
In this study, for the first time, we present a systematic study of the critical current density $J_c$ at two magnetic field orientations $B\parallel ab$ and $B\parallel c$ in a single crystal of the superconducting pnictide EuCsFe$_4$As$_4$, which shows a magnetic ordering below $T_c$ and belongs to the 1144 family. The anisotropy of $J_c$ and its temperature dependence are determined. The exponents $\alpha $ of the ${{J}_{c}}(B)$ dependences from 0.1 to 1 T are in a good agreement with the theoretical predictions for strong Abrikosov vortex pinning, which is also confirmed by the values of the pinning strength estimated using the Dew-Hughes model.