Superconductivity in Ca0.5La0.5FBiSe2

Through the measurement of resistivity, magnetic susceptibility, and Hall effect, we discovered a novel BiSe2-based superconductor Ca0.5La0.5FBiSe2 with T c of 3.9 K. A strong diamagnetic signal below T c in susceptibility χ(T) is observed indicating the bulk superconductivity. The negative Hall coefficient throughout the whole temperature regime implies the dominant electron-type carriers in the sample. Different to most of BiS2-based compounds where superconductivity develops from a semiconducting-like normal state, its resistivity in the present compound exhibits a metallic behavior down to T c . Together with the enhanced T c , the metallic character of the normal state implies that the electronic structure of Ca0.5La0.5FBiSe2 may be different to those in the other BiS2-based compounds.