The nanopowders of Y

2

O

3

:Eu

3+

with different co-dopants (Li

+

Na

+

K

+

Mg

2+

Sr

2+

Ba

2+

B

3+

and Al

3+

) were prepared by glycine-nitrate solution combustion synthesis. Structure and luminescent properties

such as the location of charge transfer band (CT band)

fluorescent intensity and lifetime of

5

D

0

7

F

2

were studied and compared each other. The detail contents were discussed as follows: 1. The nanocrystalline Y

2

O

3

were cubic in symmetry by X-ray powder diffraction (XRD) pattern. The average particle sizes estimated by Scherrers equation indicated that co-dopants could finely adjust the average particle size. That is

co-doping of Mg

2+

and Al

3+

ions decreased the combustion temperature

as a result that the size of the particles decreased. However

co-doping of Li

+

Na

+

and K

+

increased the combustion temperature and the particlessize. 2. The excitation and emission spectra were measured. Compared to undoped particles

the charger transfer (CT) band exhibited blueshift in most of doped ones. For Li

+

-doped particles

the shift was 6 nm. The emission intensity varied strongly with co-dopants. Li

+

-

Na

+

-

K

+

-and Sr

2+

-doped powders had stronger brightness than undoped ones

B

3+

-and Ba

2+

-doped powders had no obvious intensity change

but Mg

2+

-and Al

3+

-doped powders had weaker brightness. 3. The high-resolution emission spectra were recorded under the 266 nm laser excitation. Abroader band appeared between

610

and 631 nm

which was attributed to amorphous phase. The results indicated that the co-dopants of Li

+

Na

+

and K

+

can promote the crystallinity of the samples. However

the co-doping of Mg

2+

and Al

3+

drastically causes the structure disorder. 4. The fluorescence decay curves of

5

D

0

of the samples were measured under the excitation of 266 nm laser. The lifetime of particles co-doped with Li

+

and Na

+

increased as compared to that of undoped one. However

the lifetime decreased as co-doped with other dopants. In a word

the luminescent properties

such as the location of charge transfer band (CT band)

the fluorescent intensity and lifetime of

5

D

0

7

F

2

varied with co-dopants. It can be concluded that the variation depended on co-doping by modifying the size and crystallinity of nanoparticles. And the dependence was more strongly on the crystallinity than the particle size.