Mise en evidence d'une nouvelle serie de pnictures ternaires de formule generale Ln6Ni 20X13 ( X = P, As)
Twenty five new compounds Ln6Ni 20X13, where X = P or As, were synthesized. They crystallize with the hexagonal Zr 6Ni 20P 13 type of structure. Their lattice constants are reported. The structural model previously used for the description of the transition metal phosphides has been applied to the structural analysis of these compounds. This Ln6Ni 20X13 structure derives from the Rh 20Si 13 one by filling up the empty prismatic sites in the same manner as the Ln2Ni 12X7 structure derives from the Cr 12P 7 structure.