Superlubricity of Fullerene Intercalated Graphite Composite

A novel superlubric system of fullerene intercalated graphite composite is reported. First, it is clarified that fullerene intercalated graphite films exhibit an ultralow average friction force and an excellent friction coefficient µ<0.001 smaller than µ<0.002 for MoS2 and µ\cong0.001 for graphite. Next, it is demonstrated that superlubricity can be controlled by changing the intercalant species. The C60 intercalated graphite film shows much less maximum static friction force than the C70 intercalated graphite film. Finally, we propose one of the simple guidelines on designing a practical superlubric system–reduction in the contact area between the intercalated fullerene and the graphite sheet to the pointlike contact. Our newly developed superlubric system will contribute to solving energy and environmental problems.