Recently

the study of nanometric luminescent materials has become of great interest.First

the microstructural characteristics of the phosphors

such as the size or the surface properties of the grains

play an important role in the efficiency of luminescent devices.Second

new developments such as electroluminescent devices

or biological labels imply the developments of new phosphors whose properties can be managed at the nanometric scale.So it is very exigent to develop a process that can produce particles having controlled characteristics such as morphology

composition and size for good luminescent characteristics.The choice of lanthanum phosphate was made because of the excellent luminescent properties of the bulk matrix when doped with Eu

3+

.A new gel-network precipitation method was presented to synthesize the precursor of LaPO

4

:Eu nanoparticles

based on the use of lanthanide salts and(NH

4

)

2

HPO

4

in water along with gelatin used as the disperser.Then products with nicer luminescence were successfully obtained under mild calcining conditions.TEM images showed that the nanoparticles are basically monodisperse

and have good homogeneity with an average diameter of 50 nm.The Eu

3+

-doped LaPO

4

phosphor was characterized by powder X-ray diffraction.According to our measurements with XRD

the products belong to monoclinic monazite type

it is consistent with space group

P

21/n.The excitation and emission spectra were measured.Under 396 nm radiation excitation

the emission spectra of LaPO

4

:Eu consists of the sharp line emissions in the range of 500～720 nm from the transitions of electrons in 4f shell of Eu

3+

.The main peak at 592 nm can be attributed to the

5

D

0

7

F

1

transition of Eu

3+

.The excitation spectra of Eu

3+

5

D

0

7

F

2

transition emission have two parts

the wide band at 264 nm and the sharp line at 396 nm.The wide band includes both charge transfer excitation of PO

3-

4

and charge transfer excitation of Eu

3+

while the sharp line originate from Eu

3+

f-f electron transitions

which indicate that there is energy transfer from host lattice to activator in the process of luminescence.The luminescence data indicate the optimum condition for heat-treatment of the precursor was at 850℃ for 0.5 h.The effects of different content of Eu

3+

on the luminescence of LaPO

4

:Eu nanoparticles were also investigated

and the(results)show that luminescence intensity is enhanced with the increasing of Eu

3+

content.