Nonmonotonic temperature dependence of critical current in superconducting Fe(Se$_{0.3}$Te$_{0.7}$)$_{0.82}$

A nonmonotonic temperature dependence of the critical current in layered crystals of iron-based superconducting Fe(Se$_{0.3}$Te$_{0.7}$)$_{0.82}$ solid solution has been observed in the direction perpendicular to layers. This behavior is caused by the alternating sign of the superconducting current, which is due to an interaction between the electron spin in Cooper pairs and the magnetic exchange related to the sublattice of interstitial iron atoms. A change in the direction of the applied voltage leads to enhancement of the Josephson current.