PRESSURES DEPENDENT X-RAY STUDIES OF ALKALI-GRAPHITE INTERCALATION COMPOUNDS

Hydrostatic high pressure X-ray measurements up to 12 kbar were performed on CsC//8 and CsC//3//6 at ambient temperature, using a Bassett diamond anvil cell. Results for CsC//3//6 show the formation of a cesium intraplanar 2 multiplied by 2 superlattice which induces a staging phase transition. The observed splitting of the (00l) Bragg peaks is attributed to the formation of a stage 4 phase. The phase transition was found to be reversible and sample dependent. The compressiblity, of CsC//8 was measured to be (1. 57 plus or minus 0. 05) multiplied by 10** minus **1**2 cm**2/dyne. No structural phase transition was observed in CsC//8.