L. Duclaux et al., LOW-TEMPERATURE STRUCTURES OF STAGE-2 CESIUM GRAPHITIDES WITH VARIOUSCOMPOSITIONS, Molecular crystals and liquid crystals science and technology. Section A, Molecular crystals and liquid crystals, 244, 1994, pp. 313-318
Compounds with the compositions CsC22, CsC24, and CsC28 were synthesiz
ed from H.O.P.G platelets and characterized by X-ray diffraction. All
the specimens are basically 2nd stage phases. CsC24 appears as an almo
st pure phase, whereas CsC22 and CsC28 contain respectively a trace of
1st stage CsC8, and a relatively large amount of 3rd stage phase. Fou
rier analysis of the 00l reflexions shows that the composition range f
or the 2nd stage compound seems to be very limited, and close to CsC24
. From the 00l scans realized in the range 300 K-77 K, a first order t
ransition was observed for the 2nd stage phase at about 155 K, giving
two new 2nd stage phases, respectively with Ic=9.33 Angstrom (main pha
se), and Ic=9.58 Angstrom. This transition is attributed to the freezi
ng of the cesium film leading to a 2D segregation inside a unique grai
n. The domains could be separated by pleats distributed along a canted
front.