Cadmium lattice substitution

It is the very property that cadmium and sulfur can be lattice substituted to a considerable extent by members of their own Periodic Groups that gives rise to the broad range of colors possible in the cadmium palette. 

The luminescent properties can be influenced by the nature of the activators and coactivators, their concentrations, the composition of the flux, and the firing conditions. In addition, specific substitution of zinc or sulfur in the host lattice by cadmium or selenium is possible, which also influences the luminescent properties. Zinc sulfide is dimorphic and crystallizes below 1020 °C in the cubic zinc-blende structure and above that temperature in the hexagonal wurtzite lattice. When the zinc is replaced by cadmium, the transition temperature is lowered so that the hexagonal modification predominates. Substitution of sulfur by selenium, on the other hand, stabilizes the zinc-blende lattice. 

Substitution of the lattice cadmium ions in a CdS colloidal particle by the ions of another metal is often accompanied by the formation of the so-called coated particles CdS/MexSy. Such particles are readily produced via the substitution of cadmium ions by other ions if only their sulfide are less soluble compared to the cadmium sulfide. Our studies on the luminescence properties of such particles and regularities of their luminescence... 

On the basis of ionic radius, cobalt ion should be placed between copper and cadmium ions, and thus it has a higher affinity than expected. Perhaps it substitutes the iron(II) of crystal lattice since the two ionic radii are about the same (0.84 nm). 

The similarity between cadmium profiles and nutrient profiles has been used as a means of reconstructing past patterns of primary production and nutrient cychng. Several attempts have been made to reconstruct phosphate concentrations from the Cd Ca ratio of foraminifera (Boyle, 1988 Elderfield and Rickaby, 2000). Foraminifera substitute Cd for Ca in the lattice of their calcite tests, and the ratio of Cd Ca incorporation varies with the Cd Ca ratio of seawater (Boyle,... 

The replacement of some cadmium with zinc ions in the CdS lattice produces a shift in color from deep yellow to pale primrose. Similarly, the partial substitution of sulfur for selenium in the lattice produces progressively deeper red shades. 

One of the principal reasons for this study was to inquire if Cd spin-lattice relaxation represented a serious problem for high field applications of Cd NMR spectroscopy in bioinorganic chemistry. To this end, we have investigated the field dependence of the Cd Tj in cadmium substituted Con A. The... 

As the carbonate content of the ore increases, the substitution of carbonate in the francolite tends to increase. It is common for trace quantities of heavy metals, toxic elements such as cadmium, and radionuclides such as uranium to exist in phosphate rock owing to substitution in the crystal lattice (see Table 10.5). Usually the quantities of these elements are insufficient to be of concern. 

CdTe is a crystalline compound with a cubic zinc blende (sphalerite) crystal structure (lattice constant of 6.481 A), a direct band gap of 1.5 eV, an ideal match to the solar spectrum, and an extinction coefficient around 5 x 10" cm . " ° The intrinsic defects include cadmium interstitials and cadmium vacancies, and extrinsic doping can be achieved using In (donor) substitution or Cu, Ag, Au (acceptor) substitution for Cd. The mobilities have been measured to be up to 1100 cm s for electrons and up to 8 cm s for holes. Dopant densities up to 10 cm ... 

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