Synthesis of lithium- and pyridine-intercalated superconductors Li x (C5H5N) y SnSe2

Abstract Superconductors Li x (C 5 H 5 N) y SnSe 2 ( x = 0.3–1.0) have been successfully synthesized by the intercalation of pyridine molecules together with Li + ions into an insulator SnSe 2 with the layered structure. The co-intercalation has been carried out by immersing powdery SnSe 2 and Li metal in the organic solvent pyridine at 70 °C. The spacing between the adjacent Sn layers is expanded from ∼6 to ∼12 Å through the co-intercalation. It has been found that the superconducting transition temperature T c ∼ 7.5–7.9 K is almost independent of Li-content x (Li) and the superconducting volume fraction has a maximum at x (Li) = 0.5.