Crystal structure and Ce

3+

Tb

3+

-doped luminescence of NaZnLa(PO

4

)

2

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.