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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

An investigation into the luminescence and structural properties of alkali earth metaniobates

Soumonni, Ogundiran 14 May 2004 (has links)
A comprehensive investigation was reported into the synthesis, characterization and photoluminescence properties of calcium metaniobates and associated alkali earth alloy systems. Previous studies have shown that calcium metaniobate exhibits a strong self-activated blue luminescence at room temperature in stark contrast to the pyroniobates which are known to exhibit a temperature dependent luminescence that quenches above 100 K. The mechanism of this behavior has been studied by measuring the spectral characteristics of the photoluminescence and photoluminescence excitation spectra on the crystalline and morphological properties of the powders as determined from x-ray diffraction and scanning electron microscopy. By correlating the synthesis parameters with the physical, chemical and optical properties of calcium metaniobate, the optimum conditions for efficient blue-visible emission and chemical stability under vacuum ultraviolate (VUV) radiation has been determined. These materials have the potential to replace Barium Magnesium Aluminate, which is currently used as the blue phosphor in plasma displays.

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