Sur le systeme LiClVCl2

The phase diagram of the system LiClVCl2 has been investigated by X-ray diffraction on slowly cooled and quenched samples, as well as by D.T.A. measurements. In the solid state three homogeneity ranges have been observed, all with a c.f.c. anionic packing. The first one corresponds to the presence of V2+ ions and vacancies in a Li-deficient LiCl type structure, this appearing to be disordered at high temperature and more or less ordered at lower temperature. The second range is a deficient spinel-type solid solution, in which there occurs another kind of ordering between cation and vacancies in both the octahedral and tetrahedral sites. The last range corresponds to an insertion of Li+ ions in a CdCl2 type lattice, with a lamellar arrangement of divalent cations in the octahedral sites. The significant degree of disorder, which characterizes all these solid solutions at high temperature may be expected to lead to high mobility of the Li+ ions.