Sur une famille de tellurures ternaires formes par le gallium avec l'etain II, le plomb ou l'indium I, de type SnGa 6Te 10

Abstract

Two isostructural compounds are observed in the phase diagrams of the systems Ga 2Te 3-SnTe and Ga 2Te 3-PbTe. They have the general formula MGa 6Te 10 (M = Sn″ or Pb). They present a peritectic decomposition, at respectively 695 et 725°. The crystal structure is solved for SnGa 6Te 10. The rhombohedral cell, space group R32, contains 2 formulas ; a = 10.207 A ̊ , α = 89,74°. Gallium atoms are inside fully occupied tetrahedral sites. Tin atoms partially occupy, in a disordered way, 2 octahedral sites. The same structural type is observed for In 2Ga 6Te 10, in which all the octahedral sites are filled.