Cubic lead fluoride(β-PbF

2

) crystal is known as an excellent Cherenkov radiator with a radiation length of less than 1 centimeter. It is also a very attractive material for use as a scintillator because of its high density. Unfortunately no luminescence has been detected at room temperature so far. Its luminescence existing at liquid helium temperature is rapidly quenched upon raising the temperature. Someone proposed that the luminescence of crystal is hidden as a consequence of the too high local symmetry of the Pb

2+

: ions in the fluorite lattice. In order to try to break this local symmetry

a few of cation ions

such as turbium

were doped into β-PbF

2

crystal to replace the Pb

2+

: ions. In this experiment

TbF

3

was used as a dopant.β-PbF

2

crystals doped with Tb

3+

ions (β-PbF

2

:Tb) were grown with a non vacuum Bridgman method employing resistive heating system. The dopant concentration varies from 0.008 to 0.6 at%. The crucible charged with raw materials and trace deoxidant were heated to the temperature over the melting point of lead fluoride and then lowered at the rate of 1mm/cm. The grown crystal ingots were colorless and transparent. They were cut and polished to make a sample with the size of Φ25×25mm for various test. Their absorption and emission spectra excited by X-ray and UV were measured at room temperature respectively. It was found that there are seven absorption bands peaked at 283

303

318

340

352

368 and 377nm and their absorption intensity increase with the dopant amount of Tb

3+

ions from 0.1% to 0.4%(at.). The optical absorption of β-PbF

2

:Tb crystals on the UV light is corresponded to 4f-4f transition of Tb

3+

ions. There are nine emission peaks with wavelength of 382

416

437

468

489

545 and 620nm in the emission spectra excited by X-ray. It is suggested that these emission peaks result from the transition of

5

D

3

→

7

F

J

and

5

D

4

→

7

F

J

(

J

=6

5

4

3

2)

respectively. When the dopant concentration is less than 0.2at.%

the emission from

5

D

3

→

7

F

J

is dominating

otherwise

the emission from

5

D

4

→

7

F

J

is dominating. In the identical doping crystal

the fluorescence intensity decreases from the bottom to the top of the crystal. It behaves like that the segregation coefficient of Tb

3+

ion in β-PbF

2

crystal is greater than 1. The emission and excitation spectra excited by UV light were recorded by PERKIN ELMER LS50B fluorescence spectrophotometer. Four emission peaks with wavelength at 382

415

437 and 545nm were identified in the emission spectra and were ascribed to the transition of

5

D

3

→

7

F

J

(

J

=6

5

4)and

5

D

4

→

7

F

J

respectively. Tb

3+

ions in β-PbF

2

:Tb crystals are suggested to take the position of Pb

2+

: ions and the charge deficiency could be compensated by the formation of interstitial fluorine ions.