The transport properties in antimony doped iron selenide Fe(Se1−xSbx)0.92 system

The transport properties in the nominal composition Fe(Se1−xSbx)0.92 (x = 0, 0.05, 0.1, 0.2) system were studied. An abnormality was found on the resistivity curve which was ascribed to the structural transition. It was found that doping with Sb could change the transition temperature of structure transition Ts, while at the same time the change of superconducting transition temperature shows the same tendency. This may suggest that the structural transition and superconductivity has an internal relationship in the iron-based superconductors. Furthermore, two transport behaviors were found up and below structure transition like been reported in cuprates, organics, and 122-phase iron-based superconductors. This might be due to the magnetic order. At last, an insulator–metal transition was found at high temperature, suggesting a strong electron–phonon coupling in this system.