Stage transformation and staging disorder in graphite intercalation compounds.
Stage purity and staging transitions of potassium-graphite intercalation compounds have been investigated in situ by high-resolution x-ray scattering. The positions and profiles of (00L) Bragg reflections indicate staging disorder in thermal equilibrium for all compounds larger than stage 2, which increases with increasing stage number. The transition region between stages exhibits a miscibility gap for stage mixing whose size decreases with higher stages. The results are compared with recent theories on the staging of graphite intercalation compounds.