Order-disorder transformations in rubidium and caesium graphites

Abstract

Intercalated layers of alkali metals in C₂₄Rb and C₂₄Cs are disordered (liquid-like) at room temperature but undergo a reversible transformation to an ordered state (freeze) at −114 °c and −110 °c respectively. The origin of structural differences between the ordered form II of these compounds and that of the corresponding potassium compound, C₂₄K, is discussed.