The photoluminescence of the Ce

2

O

3

·yAl

2

O

3

(where

y

=12±4)system has been investigated in some detail.The materials were prepared by mixing SP gradeα-A1

2

O

3

and Ce oxalate in appropriate ratio ard sintered at 1400~1600℃ under reducing atmosphere for 2~3 hours.It was found

in the range studied

the compounds having Al

3+

/Ce

3+

ratio of about 10~11

showed optimum emission intensity under UV 254nm excitation.However

the ratio of Al

3+

/Ce

3+

has little effept pn the PL emission spectral energy distribution

which peaks all about 454nm

with half height width of 113nm.In order to improve further the luminescence intensity

actions of some fluxes(such as H

3

BO

3

CaF

2

LiF

MgO or their combinations)on these materials were studied.It was showed

when these fluxes in the range of 5m/o of the material

were added respectively to the stoichiometric CeAl

11

O

18

compound

all gave good effect

even if the sintering temperature decreased by 100~200℃.In particular

the materials fluxed with 5m/o H

3

BO

3

+5m/0 CaF

2

mixture gave an intensity of 21% superior to that of CaWO

4

:Pb under the same excitation condition.The crystal structures of these phosphors based on this system were determined by means of X-ray powder diffraction method.The principal phase existed in these compounds was identified to be isomorphous with magnetoplumbite

which has a hexagonal ferrite structure with stoichiometric composition CeAl12O195

>

α

=5.561A

c

=21.980A

Dx=4.09g/cm

2

Z

=2.It was also found that there was no continuous solid solution existed

as showed by work [2].This type of material is an efficiently blue-emitting phosphor under UV 254nm excitation

its PL is not so sensitive to contamination that the CP grade

instead of SP grade

raw materials give also satisfactory results.Consequently

the cost of this phosphor may reduce to reasonable level and suitable for large-scale production.These finally make it possible to be used in fluorescent lamp.