When preparing phosphor yttrium aluminum garnet Y

3

Al

5

O

12

(YAG)activated with cerium(Ce

3+

)by solid-state reactions

the fluxes addition has great influence on the ion diffusions

crystallization process as well as on the formation of YAG matrix with good crystallinity.As a result

the crystallite size distribution and luminous efficacy of the phosphor as well as the hardness of the product are closely relative to the flux applied.It is known that the YAG:Ce phosphor prepared by solid-state reaction using H

3

BO

3

as a flux often exhibited high hardness

causing many troubles in post-treatment.In this paper

YAG:Ce phosphors with the same Y/Al atomic ratio and the same atomic fraction of Ce were synthesized using different fluxes including a series of fluorides fluxes(such as MgF

2

CaF

2

SrF

2

BaF

2

AlF

3

)and mixed fluxes of fluorides with H

3

BO

3

.Effect of types and concentrations of the flux on the morphology

crystallite and luminescent properties of YAG:Ce were studied.It was found that the phosphors prepared with the fluxes studied in this work exhibited typical crystal structure of garnet and no impurity phase was detected.The excitation and emission spectra of the phosphors with different fluxes were roughly same.The main differences of the phosphors prepared with different fluxes were the hardness and luminescent brightness of the products.The luminescent brightness was higher while the hardness was lower for the YAG: Ce phosphor prepared with BaF

2

AlF

3

SrF

2

and their mixture with H

3

BO

3

compared with that using H

3

BO

3

as flux alone.It is supposed that from the practical application point of view

BaF

2

AlF

3

SrF

2

and their mixture with H

3

BO

3

were the better fluxes for YAG:Ce among all fluxes investigated.