1203.5046 (Matthew Burrard-Lucas et al.)

Enhancement of superconducting transition temperature of FeSe by
intercalation of a molecular spacer layer    [PDF]

Matthew Burrard-Lucas, David G. Free, Stefan J. Sedlmaier, Jack D. Wright, Simon J. Cassidy, Yoshiaki Hara, Alex J. Corkett, Tom Lancaster, Peter J. Baker, Stephen J. Blundell, Simon J. Clarke

The recent discovery of high temperature superconductivity in a layered iron arsenide has led to an intensive search to optimize the superconducting properties of iron-based superconductors by changing the chemical composition of the spacer layer that is inserted between adjacent anionic iron arsenide layers. Until now, superconductivity has only been found in compounds with a cationic spacer layer consisting of metal ions: Li+, Na+, K+, Ba2+ or a PbO-type or perovskite-type oxide layer. Electronic doping is usually necessary to control the fine balance between antiferromagnetism and superconductivity. Superconductivity has also been reported in FeSe, which contains neutral layers similar in structure to those found in the iron arsenides but without the spacer layer. Here we demonstrate the synthesis of compounds (LiNH2)xFe2Se2 (0.8View original: http://arxiv.org/abs/1203.5046