CAO Jin-quan, WANG Shu-bin, TIE Shao-long, SU Qiang. Luminescence of Ce<sup>3+</sup> and Tb<sup>3+</sup> in NaZnLa(PO<sub>4</sub>)<sub>2</sub>[J]. Chinese Journal of Luminescence, 2000,21(4): 288-292
CAO Jin-quan, WANG Shu-bin, TIE Shao-long, SU Qiang. Luminescence of Ce<sup>3+</sup> and Tb<sup>3+</sup> in NaZnLa(PO<sub>4</sub>)<sub>2</sub>[J]. Chinese Journal of Luminescence, 2000,21(4): 288-292DOI:
prepared through conventional high-temperature solid state reaction were investigated. The cell parameters calculated from the powder X-ray diffraction pattern of NaZnLa(PO
4
)
2
are
a
=0.6823nm
b
=0.7045nm
c
=0.6497nm
β=103.9°
V
=0.303nm
3
.Its cell constants and unit-cell volume are comparable to those of monoclinic LaPO
4
with monazite-type. The fact that NaZnLa(PO
4
)
2
is isostructure with LaPO
4
is also identified by IR. The IR spectrum of NaZnLa
0.78
Ce
0.1
Tb
0.12
(PO
4
)
2
(see table 2) are similar to that of LaPO
4
and the local site symmetry of PO
4
also belongs to Cs. The luminescence of Ce
3+
Tb
3+
-doped NaZnLa(PO
4
)
2
showed that the Ce
3+
ion has a strong f-d absorption band around 250~320nm and its
5
d →
7
F
j
(
j
=7/2
5/2) emission band overlaps with Tb
3+
4f-4f excitation spectrum. Thus green emission of Tb
3+
can be efficiently sensitized by Ce
3+
. The optimum concentrations of Ce
3+
and Tb
3+
in NaZnLa
1-x-y
Ce
x
Tb
y
(PO
4
)
2
were
x
=0.2~0.4 and
y
=0.08~0.16
respectively. The green emission of Tb
3+
can also be enhanced by co doping with appropriate amount of BO
3
3-
(~0.12 mole/formula)
Al
3+
(~0.04 mole/formula)
and Dy
3+
(~0.001 mole/formula). Comparing with LaPO
4
the synthesis temperature of NaZnLa
1-x-y-z-w
Ce
x
Tb
y
Dy
z
Al
w
(PO
4
)
2
-
v
(BO
3
)
v
is lower and the consumption of rare earth used for synthesis is less because part of rare earth is substituted by Na and Zn.