CHALKOGENIDES OF THE TRANSITION ELEMENTS: III. MOLYBDENUM DITELLURIDE

MoTe 2 prepared by dry synthesis from the elements at 460 °C and annealed at 600 °C has a layer structure of the C7 type with a 0  = 3.5182 ± 14 Å and c 0  = 13.9736 ± 40 Å. The parameter of the tellurium atom has been determined from closely reproducible X-ray diffractometer powder intensities as 0.621 ± 1. The nearest-neighbor co-ordination polyhedron of the molybdenum atom is a trigonal prism with a Mo—Te distance of 2.716 ± 12 Å. The distance of nearest approach of the tellurium atoms between layers is 3.945 ± 25 Å and thus greater than the similar distance between chains in metallic tellurium. It is shown that the observed intensities are not compatible with a stacking sequence of the C27 type, which differs from the C7 arrangement in the geometry of the co-ordination polyhedra of the metal atoms.