On the road of optimization of phosphors for fluorescent lamps, we studied the blue one which formula is Ba0.9Eu0.1MgAl10O17. First of all, our work consisted on studying the effect of some fluxes upon the microstructure and the structural properties and the consequences upon the optical performance of the material. The second part of the word is the study of the main problem of this phosphor : its loss of luminescence during the baking (annealing at high temperature under air). If the cause of this deterioration have already been identified, which is the oxidation of the dopant, however the mechanisms leading to it are still scarce. In order to find a suitable solution for industry, we must understand the phenomenon occurring during the baking. By combining several techniques, we managed to elaborate a model to explain the oxidation, and we even suggest a simple solution to reducing the loss. Finally, we studied the material while the lamp is in function. The loss of brightness of the fluorescent lamp is not due to the deterioration of the phosphor, but due to the consummation of mercury. Our work can be applied to the other phosphors
