Stage Order, Disorder, and Phase Transitions in Intercalation Compounds

A theoretical study of intercalation predicts stage-changing phase transitions to be continuous and to proceed via stage-disordered states. Detailed results are presented for typical donor and acceptor graphite intercalation compounds. Other systems are also discussed. A scaling rule relating stage disorder to domain size, stage, temperature, in-plane density, and charge transfer is proposed. A fundamental limit is set on the period of well staged structures. Experimental implications are discussed.