Cerium niobate

Pyrochlore.—This is a crude calcium niobate which may also contain appreciable quantities of titanium, thorium and cerium, together with smaller quantities of iron, magnesium, the alkali metals, and fluorine. It does not contain chlorine, and it is of interest in that some specimens are remarkably free from tantalum. It occurs in Norway and near Miask in the Ural Mountains. The ore is brown, forms regular octa-... 

In addition to the foregoing, more or less impure niobates of beryllium, cerium, lanthanum and nickel have been prepared.12... 

Figure 9.2 Polarization-isotropic photo-induced light scattering in strontium-barium-niobate doped with 0.66 mol% Cerium (SBN61 Ce). Strongly amplified scattered light occurs in a wide solid angle opposite to the polar c-axis. The label denotes the apex angle measured with respect to the directly transmitted laser beam in air. Ap = 632.8 nm, Ep c. The insets show a photograph of the sbn crystal (left) and the schematic setup of the experiment (right), respectively.

Figure 9.3 Polarization-isotropic photo-induced light scattering in strontium-barium-niobate doped with 0.66mol% Cerium at different times of illumination. Here, the wavelength Ap =...

In 1877, Mallet discovered an yttrium niobate mineral called sipylite in Virginia (USA). Analyzing it he found that it contained niobium and cerium and yttrium group elements (Mallet 1877). In 1878, Delafontaine identified Marignac s ytterbium in this mineral too (Delafontaine 1878d). 

Strontium cobalt ferrites are good mixed conductors but are more suitable to be used as cathodes due to their p-type conduction. Pervoskite gaUates/niobates/barium cerate and chromium-doped lanthanum-strontium ferrite have also been studied as the anode material. Although the gaUates and niobates exhibit low conductivity, they exhibit good compatibihty with the LSGM electrolytes. The conductivity of yttrium-doped barium cerates increases by increasing yttrium content. For barium cerates, the increase in electronic conduction due to the reduction of cerium at low... 

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