BaAl
12O
19 is considered to be a mixture of a Ba-poor aluminate (0.82 BaO·6 Al
2O
3) and a Ba-rich aluminate (
xBaO·6Al
2O
3, x=1.30±0.2). Because the Ba-poor aluminate and BaMgA1
10O
17 (BAM) have exactly the same crystal structure as β-alumina, both compounds form solid solutions with it. In this study, we prepared various kinds of solid solutions of the Ba-poor aluminate and BAM in which Mn
2+ was substituted for some or all of the Mg
2+. These formulae can be expressed as (1-α) (0.82BaO·6Al
2O
3)·α (BaMg
1-βMn
βAl
10O
17). Their emission properties under 146 nm excitation were studied. As α and β were changed with a constant Mn
2+ content in the phosphor (α·β=0.12), two kinds of bright solid solutions were found. One was a BAM-poor solid solution (α=0.12, β=1.0) and the other was a BAM-rich solid solution (α=0.92, β=0.13). Substituting Sr
2+ for Ba
2+ improved the luminance of the BAM-rich solid solution. For example, the composition of a BAM-rich solid solution in which Sr
2+ replaced 76% of the Ba
2+ was Ba
0.24Sr
0.75Mg
0.80Mn
0.12A1
10.2O
17.21. Comparing the properties of this phosphor with those of the conventional BaAl
12O
19: Mn, we found the luminance was 18% higher, the chromaticity was purer green (
x=0.146,
y=0.749) and the 1/10 decay time was equivalent (14 ms). This material should serve as a new green phosphor for PDPs, though its lifetime in PDPs remains to be measured.
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