First stage intercalation compounds were obtained using vapor reaction of heavy alkali metals (M = K, Rb and Cs) with BxC1-x platelets (x = 0.1 and x = 0.25). Depending on the value of x, M(B0.1C0.9)(8 +/- 1) and M(B0.25C0.75)(10 +/- 1) compounds were formed. Intensity calculations of the 00l lines suggested domains of M(BxC1-x), first stage dense structure. As formed B0.25C0.75 was incompletely intercalated by cesium from its liquid ammonia solution whereas extended intercalation was obtained with heat treated B0.25C0.75 host (T = 1600 degrees C) giving a first stage derivative.
Duclaux, L., Ottaviani, B., Piraux, L., Grivei, E., Issi, J.-P., Béguin, F., & Flandrois, S. (1998). Intercalation of heavy alkali metals in boron substituted carbons BxC1-x. Molecular Crystals and Liquid Crystals Science and Technology. Section A. Molecular Crystals and Liquid Crystals, 310, 27-32. https://doi.org/10.1080/10587259808045310 (Original work published 1998)