Superconductivity in alkali-metal-doped picene

Efforts to identify and develop new superconducting materials continue apace, motivated by both fundamental science and the prospects for application. For example, several new superconducting material systems have been developed in the recent past, including calcium-intercalated graphite compounds (1), boron-doped diamond (2) and-most prominently-iron arsenides such as [LaO.sub.1-x][F.sub.x]FeAs (ref. 3). In the case of organic superconductors, however, no new material system with a high superconducting transition temperature ([T.sub.c]) has been discovered in the past decade. Here we report that intercalating an alkali metal into picene, a wide-bandgap semiconducting solid hydrocarbon, produces metallic behaviour and superconductivity. Solid potassium-intercalated picene ([K.sub.x]picene) shows [T.sub.c] values of 7K and 18 K, depending on the metal content. The drop of magnetization in [K.sub.x]picene solids at the transition temperature is sharp (
The metal doping of organic molecular compounds and graphites, solids with p-electron networks, has been extensively studied in the search for novel physical properties, such as metallic behaviour and superconductivity [...]