Insertion of potassium in pure C60 single crystals

Abstract Pure C 60 single crystals have been obtained from benzene solution and characterized by X ray measurements. An hexagonal structure which is a multiple of the well established fcc structure is confirmed. These crystals (which have a platelet form) are very brittle and sensitive to the potassium insertion: whatever the temperature of insertion (from 100°C to 200°C), the single crystal was completely broken and a saturated K 6 C 60 phase has been characterized.