Chemical, structural and electrical resistivity of two first stage arsenic–potassium–graphite intercalation compounds

• Intercalation reaction between graphite liquid arsenic–potassium alloys has been studied.
• Two ternary phases of first stage have been observed and synthesized.
• A theoretical model based on calculation of c-axis electronic density profile by using 00l reflexions intensities is used to access to determination of atomic stacking structure of intercalated alloy along c-axis direction.
• hk0 reflexions family of mono-crystal and poly-crystal synthesized compounds have been recorded by using different X-ray methods and electronic diffraction microscopy, we determined the in-plane crystallization nature of intercalated metallic sheets in parallel direction to graphitic layers.
• Electrical resistivity measurements along c-axis and in parallel direction of graphitic layers have been carried out on two synthesized phases.

The action on graphite of liquid arsenic–potassium alloys leads to the formation of a new series of graphite intercalation compounds. Two ternary phases of first stage have been observed and isolated. The α-type phase is obtained by action on graphite of composition alloys close to that of defined K3As compound. On the other hand, the β-phase is easily obtained by action on graphite of K–As alloys whose chemical stoichiometry is equal or near to the 37 at.% As eutectic point composition.The Fourier transform analysis of the 00l reflexions family of these two phases showed that the intercalated metallic sheets between graphitic gaps in these phases are generally three-layered stacking according to K/As/K sequence along c-axis. An exam, by means classical X-ray diffraction and transmission electronic microscope (TEM) of the in-plane structure of these compounds revealed that the intercalated metallic sheets are perfectly crystallised and an equatorial stratum was defined for each of them.Electrical conductivity measurements have been carried out on these phases along both axis of graphite and showed that they are strongly anisotropic and exhibit a metallic character in parallel to graphitic plans.