LIN Hai-yan, LI Dian-chao, QIN Wei-ping, ZHANG Ji-sen, WU Chang-feng, QIN Guan-shi, ZHAO Dan, LIU Huang-qing. Spectral Properties of Eu<sup>3+</sup>-doped Borate Crystal and Glass[J]. Chinese Journal of Luminescence, 2003,24(5): 512-516
LIN Hai-yan, LI Dian-chao, QIN Wei-ping, ZHANG Ji-sen, WU Chang-feng, QIN Guan-shi, ZHAO Dan, LIU Huang-qing. Spectral Properties of Eu<sup>3+</sup>-doped Borate Crystal and Glass[J]. Chinese Journal of Luminescence, 2003,24(5): 512-516DOI:
The local structure of rare-earth ions in solid host is of great research interest for designing new luminescence materials
and Eu
3+
ion is a good probe to reflect the local environment around rare-earth ions in different materials. In this paper
Eu
3+
-doped La
2
O
3
-3B
2
O
3
crystal and glass samples were prepared by solid-state reaction under different calcination temperatures. By controlling calcination temperatures at 960℃ and 1 200℃
respectively
the crystal and glass samples with the same composition were obtained. The Eu
3+
ions in the two samples present different flourescent properties. With the excitation of 394nm ultra-violet light
the glass sample presents an intense 618nm emission
while the crystal sample gives a dominant 696nm emission. The emission spectra
the phonon sideband spectra
the charge transfer bands and the lifetimes were measured to clarify the different luminescence of the two samples. In the emission spectra
both of the two figures (Fig.1
Fig.2) present the characteristic luminescence of Eu
3+
ion
including emission peaks at 590nm (
5
D
0
→
7
F
1
)
618nm (
5
D
0
→
7
F
2
)
650nm (
5
D
0
→
7
F
3
)
696nm (
5
D
0
→
7
F
4
). Among these transitions
the
5
D
0
→
7
F
1
transition is a magnetic dipole transition
and the
5
D
0
→
7
F
2
transition is an electric dipole transition. It was found that
with the transition from crystal phase to glass phase
the intensity ratio of
5
D
0
→
7
F
2
to
5
D
0
→
7
F
2
of Eu
3+
ion was enhanced
which indicates that the value of J-O parameter Ω
2
was increased. The local structures around Eu
3+
ion in the two different host were investigated by measuring the charge transfer bands and the phonon sideband spectra associated with the
5
D
2
←
7
F
0
transition. It was concluded that B-O vibrational mode inside the various borate rings and nonbridging B-O
-1
bonds stretching mode with phonon energy of 1 900
1 500cm
-1
respectively
exist in both of the two samples. The charge transfer bands confirmed that the near coordination ions of Eu