Ce

3+

:LiSrAlF

6

crystal is a solid state laser material potentially capable of efficiently producing tunable ultraviolet (UV) output. Recent results suggest that it may be the most efficient continuously tunable

rare earth doped UV laser material reported to date. There are some defects in Ce

3+

:LiSrAlF

6

crystal. These defects will affect the laser and luminescence properties of crystal. In this paper

the temperature dependence of luminescent intensity (

I-T

) of Ce

3+

:LiSrAlF

6

crystal with X-ray excitation from 105K to 300K has been studied. The luminescent intensity is enhanced " specially " in the range of 237～300K

which is probably caused by traps. In order to verify our surmise

we investigated the thermoluminescence of Ce

3+

:LiSrAlF

6

crystal from 105～300K with X-ray excitation at 105K for two minutes. From 237～300K

two peaks locate at 258K and 274K respectively. These two peaks are accord to two kinds of traps

whose depth are 0.51eV (258K) and 0.55eV (274K). Comparing

I-T

curve with TL curve

the enhanced part of

I-T

curve is coincided with temperature range in which TL peaks locate. Because the TL peaks originate from traps

we suggest that the special structure of

I-T

curve is caused by the traps effect. That is

during the period of measuring the

I-T

at lower temperature

some charge carriers relax to luminescent center and luminesce

while some other charge carriers is captured by traps. The release probability of bonded carriers is described as Cexp(-

E/kT

)

where C is a constant

E

is the depth of trap and

T

is temperature. With the temperature rising

the bonded charge carriers will release from the traps at higher temperature

via conduct band then relax to luminescent center and give out light

which make the intensity of luminescence enhanced. The origination of defects of Ce

3+

:LiSrAlF

6

crystal is discussed too. It is primary that Ce

3+

occupies the sublattice of Sr

2+

in Ce

3+

:LiSrAlF

6

crystal

forming CeSr

3+

defect. Generally

fluorine vacancies (

V

F

) always exist in fluoride. Ce Sr

3+

and

V

F

are negative charge center

which form electron traps. The lithium vacancies (

V

Li

) are principal positive charges

which compensate the negative charge Ce Sr

3+

and

V

F

V

Li

form hole traps. In conclusion

the "special" structures of

I-T

curve in the range of 237～300K is explained by the traps effect

which is verified by means of TL. The depths of two traps are 0.51eV and 0.55eV respectively. These traps mainly originate from CeSr

3+

and some intrinsic defects such as

V

F

and

V

Li

.