Synthesis and physical property characterization of LaOBiSe2 and LaO0.5F0.5BiSe2 superconductor

• Bulk polycrystalline samples of LaOBiSe2 have been successfully synthesized by solid state reaction.
• Structural analysis shows LaOBiSe2 crystallizes in a tetragonal P4/nmm space group.
• Physical property measurement suggests a possible charge density wave transition around 120 K.

Bulk polycrystalline samples of LaO1−xFxBiSe2 (x ranges from 0 to 0.5) with nominal composition have been successfully synthesized by solid state reaction. Detailed structural analysis shows that LaOBiSe2 crystallizes in a tetragonal structure (P4/nmm) with lattice parameters of a=4.1565(1) Å and c=14.1074(3) Å. Experimental results of electrical transport demonstrate that LaOBiSe2 is a bad metal with an evident anomaly at about 120 K, while the magnetic susceptibility exhibits an evident anomaly around 120 K, suggesting a possible charge density wave (CDW) transition around this temperature. Furthermore, superconductivity is observed in LaO0.5F0.5BiSe2 sample with nominal composition at 3.1 K from magnetic and transport measurements.