Superconductivity in PbO-type Fe chalcogenides
PbO-type Fe chalcogenide has been drawing much attention as the Fe-based superconductor with the most simple crystal structure. Whereas FeSe is an intrinsic superconductor, FeTe, while having a structure analogous to FeSe, exhibits antiferromagnetic ordering. The relationship between antiferromagnetism and superconductivity provides key information to understand better superconductivity in Fe chalcogenides. Furthermore the significant pressure effect on Tc in the Fe-chalcogenide superconductors, which is likely to be correlated with the crystal structure and/or magnetism, is important in elucidating the mechanism of Fe-based superconductivity. Due to the simple structure and composition, Fe-chalcogenide superconductor is one candidate for applications to such areas as superconducting wires and thin films.