A FeSe-based superconductor (C 2 H 8 N 2 ) x FeSe with only ethylenediamine intercalated

A new FeSe-based superconductor (C2H8N2) x FeSe with ethylenediamine intercalated into FeSe was successfully synthesized by the solvothermal method, which is the first superconducting instance by metal-free organic molecule intercalation. Elemental analysis and TG-IR-GC/MS data reveal that the ethylenediamine molecules in the interlayer space are separate and intact. The X-ray diffraction (XRD) pattern indicates that the intercalation compound is an orthorhombic lattice rather than a tetragonal lattice applying to almost all the previous FeSe-based superconductors at room temperature. The magnetism measurements display a sharp superconducting transition at ∼10 K which is assigned to (C2H8N2) x FeSe, and a tiny drop in susceptibility at ∼30 K.