INTERCALATION DE-INTERCALATION PHENOMENA IN A GRAPHITE-SODIUM-OXYGEN COMPOUND UNDER POTASSIUM VAPOR

Stage 2 graphite-sodium-oygen ternary compound contains five-layered N aONaONa-intercalated sheets, that are actually slices of hexagonal Na2 O2 peroxide, cut perpendicularly to its c-axis and strongly flattened along this axis. Submitted to potassium vapour this phase allows inter calation of potassium monolayers into the empty structural gaps leadin g to an original biintercalation compound with alternatively monolayer ed and five-layered intercalated sheets. Such a metastable compound de composes then, losing first sodium and oxygen with substitution by pot assium.