Structure and Phase Transitions of Graphite Intercalated with Bromine

This paper is a review of the structure and phase transitions of graphite-bromine intercalation compounds. Emphasis is given to the room-temperature commensurate phase, the room-temperature incommensurate phase and the high temperature incommensurate phase, together with the associated intralayer commensurate-incommensurate transition (332–350 K, depending on the stage), incommensurate-commensurate transition (319 K) and melting transition (374 K). Other transitions are the interlayer order-order transition (297 K) and the interlayer disorder-order transition (277 K). Of fundamental importance are the determination of the two-dimensional structure of the commensurate phase and the successful use of domain wall models to elucidate incommensurate phases. The dependence of the structure and phase transitions on stage and sample preparation conditions is also summarized.