Crystal growth and superconductivity of FeSex

In this work, crystals of FeSex have been grown by a flux approach. The crystallization process is divided into two stages. First, stoichiometric polycrystal FeSe0.82 was sintered in a solid state reaction. Then, FeSex crystals with a size about 500 µm were successfully grown in an evacuated sealed quartz tube using a NaCl/KCl flux. The products include two crystal structures: tetragonal and hexagonal. The electronic transport and magnetic property measurements show that FeSex crystals exhibit a superconducting transition at about 10 K.