| 摘要 |
The invention is directed a composition represented by the chemical formula Eu<SUB>x</SUB>A<SUB>1-x</SUB>F<SUB>2+x-2y</SUB>O<SUB>y </SUB>wherein A is alkaline earth, 0.002<=x<=0.20, and 0<=y<=x; the composition exhibiting a luminescence spectrum characterized by peaks at 592±2 nm and 627±2 nm, wherein the ratio of the peak intensity at 592±2 nm to that at 627±2 nm is at least 5% larger than the corresponding peak intensity ratio at the same wavelengths of a first corresponding reference composition with the same value of x that has not been exposed to a temperature above 100° C., and wherein said ratio of the peak intensity at 592±2 nm to that at 627±2 nm is at least 5% smaller than the corresponding peak intensity ratio at the same wavelengths of a second corresponding reference composition with the same value of x that has been subject to heating to 900° C. for 6 hours.
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