| 摘要 |
PROBLEM TO BE SOLVED: To control lapsing deterioration on changes of luminous color and on luminous efficiency during lighting a fluorescent lamp as well as to improve coloring action and the efficiency by comprising a specific composition of Ba, Sr, Eu, Mg, Mn, Al and O. SOLUTION: A fluorescent substance is represented by a compositional formula, Ba1-x-ySrxEuyMg1-zMn2Al10O17. In the formula,(x), (y) and (z), fulfill 0.4<=x<=0.6, 0.03<=y<=0.3, 0<=z<=0.04, respectively. This fluorescent substance is obtained by mixing each oxide of Ba, Sr, Mg, Al, Eu and Mn or mixing compounds generating readily these oxides at a high temperature so as to make a stoichiometric ratio of this compositional formula, and this mixture is charged into a heat-resistant container followed by one or more of calcining at 1200-1700 deg.C for 2-40 hr in a reductive atmosphere. When this fluorescent substance is used as a blue luminous component of the luminous composition of a fluorescent lamp, the lamp which is less in lapsing deterioration with high coloring action and high efficiency, can be obtained.
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