Erbium selenides

In addition to the above, preparation in w/o microemulsions of nanoparticles of various other types of compounds, viz. silica-coated iron oxide, Fe203-Ag nanocomposite, oxides of ytrium, erbium, neodymium, vanadium and cobalt, titanates of barium and lead, ferrites of barium, strontium, manganese, cobalt and zinc, oxide superconductors, aluminates, zirconium silicate, barium tungstate, phosphates of calcium, aluminium and zinc, carbonates of calcium and barium, sulphides of molybdenum and sodium, selenides of cadmium and silver etc. have been reported. Preparative sources and related elaboration can be found in [24]. 

AgRSe2 compounds of the AgErSci-type. This structure was established, from a single crystal study, by Julien-Pouzol et al. (1977) (fig. 31.15). The flat orthorhombic cell, P2i2]2i, contains four formulas. The erbium atoms are at the center of nearly regular octahedra of selenium. The silver atoms are inside flat tetrahedra, with four nearly equal Ag-S distances. These tetrahedra form open chains along the Oz direction and constitute channels in which it might be possible for the silver ions to move. These compounds are ionic conductors. They are only known in the selenides series, from Dy to Lu, and for Y and Sc (Julien-Pouzol et al., 1969, 1973). 

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