Chalcogenides quaternary

Examples of known ternary (and quaternary) chalcogenide compounds, classified according to a formal valence combination scheme, are given in Table 1.4. These compounds were collected from a compilation of Madelung [40] regarding semiconductor materials. To be sure, numerous other systems exist. Some important ternary compounds or classes will be considered in the relevant sections of the present chapter. 

Table 1.4 Some ternary (and quaternary) semiconductor chalcogenides...

Quaternary chalcogenides of the type A Ln M X, containing three metal elements from different blocks of the Periodic Table (A is an alkali or alkaline earth metal, Ln is an /-block lanthanide or scandium, M is a p-block main group or a r/-block transition metal, and X is S or Se) are also known [65]. 

Assoud A, Soherinia N, Kleinke H (2007) Thermoelectric properties of the new teUurides SrSc2Tc4and BaSc2Te4 in comparison to BaY2Tc4. IntermetaUics 15 371-376 Wu P, Ibers JA (1995) Quaternary chalcogenides containing a rare earth and an alkali- or alkaMne-earth metal. J Alloy Compd 229 206-215... 

Narducd AA, Ibers JA (1998) Ternary and quaternary uranium and thorium chalcogenides. Chem Mater 10 2811-2823... 

Starodub VA (1999) Ternary and quaternary chalcogenides of Group IB elements. Rus Chem Rev 68 801-820... 

Solids with octahedral, tetrahedral, square planar, and linear metal coordination geometries, including many different types of polyhedra connectivity modes, are amenable to dimensional reduction. Tulsky and Long compiled an enormous database of over 300 different allowed combinations of M and X and over 10,000 combinations of A, M, and X. The formalism may be extendable to quaternary phases as well. However, frameworks containing anion-anion linkages, anions other than halides, oxide, or chalcogenides, nonstoichiometric phases, and mixed-valence compounds were excluded from their initial study. 

Crystallographic Relationships of Ternary and Quaternary Rare Earth Chalcogenides of Si, Ge, ... 

This section describes known quaternary chalcogenide systems containing silicon, germanium, tin, lead, and indium. 

The R-M-Z-X (M = Cu, Ag Z = Si, Ge, Sn, X = S, Se) systems have been investigated mainly across the R2X3-M2X-ZX2 sections. No quaternary compounds are known for Te systems. Quaternary compoimds that form in these systems are listed in Table 38. Among all of these 105 quaternary chalcogenides only four compoimds crystallize in SG other than P63. In several series of the silver compounds, occupational disorder for the silver atom has been foimd. 

The copper-containing chalcogenides crystallize in orthorhombic S3nnmetry, SG Pnma. Only one silver quaternary compound, La4Ag2lri4Si3, has been reported. It crystallizes with relatively large a and b lattice parameters. 

TABLE 39 Crystallographic data for quaternary chalcogenides of the R2X3-Cu2X-PbX (X = S, Se) systems... 

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