| Mn2+-doped barium hexaaluminate with the β-Al2O3 type structure ofhas been investigated extensively as the green component of tricolor luminescence materials. Especially with the development of plasma display panel (PDF), the green-emitting BaAl12O19:Mn phosphor has been paid more attention because it has a good efficiency under vacuum ultraviolet (VUV) excitation. Conventionally, the aluminates phosphors were prepared by solid state reaction required firing temperature in the range of 1600-1 800 ℃ because of the refractory nature of the oxide precursors. The resulting large size phosphors were ground to obtain fine powder that caused the decreasing of the luminescent efficiency. Recently, phosphors of hexaaluminates were prepared by sol-gel technique, hydrothermal processing, combustion syntheses and microwave heating method, but some disadvantages in the proceeding delayed its commercialization. Chemical coprecipitation as a solution-based method, which allows mixing of precursors at the molecular level, has an advantage in the preparation of aluminates phosphors. In this dissertation we prepared the phosphor BaAl12O19:Mn which has the β-Al2O3 type structure by chemical coprecipitation for the first time. We also conducted a series of experiments researching with the aids of the measure methods such as XRD, DTA, IR spectra. TEM and so on. The major work is summarized as the following:(1) According to the experiments, some factors in the coprecipitating process such as concentration of cations and precipitators, water-bath temperature, dropping velocity of precipitators, the pH value of the system, were discussed. It was found that the pH value is the critical factor that affects the coprecipitating process. The nanometer-size fibriform appearance of precursors through TEM can be obtained by controlling the pH value in 8-9.(2) The influence on host structure with varying firing temperature was discussed. It was found that BaAl12O19:Mn can be obtained in the temperature 1200℃ with the assist of the flux boracic acid. The superdispersing state that caused by chemical coprecipitation lowered the firing temperature about 400 ℃ contrasted with the solid-state reaction.(3) The relation between the firing temperature and the particle size wasdiscussed. The new meaningful result can be given: the superdispersing state did not only depress the temperature but also provide the chances which the BaAl12O19:Mn particles meets and coagulates; the mode which led the phosphors particles growing to products powder unlike the grinding mode would have positive influence upon the phosphors efficiency attenuation.(4) With the expression of BayMno.ojAl 11.95019+6, the correlation between host structure and the ratio of barium oxide and alumina was investigated in detail. It was at the range of 1.2 to 1.4 not of 0.82 to 1.32 according to the literatures to obtain the BaAl12O19:Mn phase. Investigation on XRD and IR spectrum revealed that there are uncrystled materials that caused the y value change in the products.In this dissertation, our creative research in the preparation of BaAl 12619:Mn gives some significant results, we hope that will give some elicitation for the further investigation of the preparation of aluminates for luminescence.
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