| CPC H10H 20/8512 (2025.01) [C09K 11/62 (2013.01); C09K 11/63 (2013.01); C09K 11/645 (2013.01); C09K 11/77346 (2021.01)] | 11 Claims |
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1. A phosphor in which at least some of an element M in a phosphor host crystal represented by Mα(L, A)βXγ is substituted with Eu, in both Eu3+ and Eu2+ states, as an activation material, the phosphor having a composition represented by Formula: Mα(L, A)βXγ:Euδ,
wherein M represents one or more elements (including at least Sr) selected from Mg, Ca, Sr, Ba, and Zn,
L represents one or more elements selected from Li, Na, and K,
A represents one or more elements selected from Al, Ga, B, In, Sc, Y, La, and Si,
X represents one or more elements selected from O, N, F, and Cl, wherein X is not only N,
α, β, γ, and δ satisfy 8.70≤α+β+γ+δ≤9.30,
0.00<α≤1.30,
3.70≤β≤4.30,
3.70≤δ≤4.30, and
0.00<δ≤1.30, and
in a fluorescence spectrum obtained by irradiation with light having a wavelength of 260 nm, when a fluorescence intensity at a wavelength of 569 nm is represented by I0 and a fluorescence intensity at a wavelength of 617 nm is represented by I1, a fluorescence intensity ratio I1/I0 is 0.01 or more and 0.4 or less,
wherein the phosphor is powdery such that, when an average particle size corresponding to a cumulative value of 50% in a volume frequency particle size distribution measured using a laser diffraction scattering method is represented by d50, d50 is from 0.1 μm or more to 50 μm or less.
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