Znang Jilin, Hong Guangyan. SPECTRAL PROPERTIES OF K<sub>2</sub>NaA1F<sub>8</sub>:Ce<sup>3+</sup> AND KAlF:Ce<sup>3+</sup>[J]. Chinese Journal of Luminescence, 1991,12(3): 224-229
Znang Jilin, Hong Guangyan. SPECTRAL PROPERTIES OF K<sub>2</sub>NaA1F<sub>8</sub>:Ce<sup>3+</sup> AND KAlF:Ce<sup>3+</sup>[J]. Chinese Journal of Luminescence, 1991,12(3): 224-229DOI:
are stoichiorr.etric host luminescent materials having high concentration of luminescent Eu
3+
ions and no noticeable concentration quenching. Raman spectra of these two materials have been studied. The symmetry species of the lattice vibration modes of Na
5
Eu(MoO
4
)
4
have been analysed by means of the group theory.The structures of both materials belong to tetragonal
I
4
I
/a (C
4h
6
) space group. For Na
5
Eu(MoO
4
)
4
the free ion symmetries of (MoO
4
)
2-
Eu
3+
and Na
1+
correlate with factor group C
4h
through their site groups. A primitive cell includes two Na
5
Eu(MoO
4
)
4
molecules. It mears that 8 (MoO
4
)
4
2-
10 Na
1+
and 2 Eu
3+
are included in the cell. So the lattice vibration of Na
5
Eu(MoO
4
)
4
in the cell can be classified into 72 internal modes and 84 external modes. For crystal factor group C