A simple technique for the preparation of powder compounds MeBeF

4

(Me=Ca

Sr

Ba) doped with divalent samarium is described. The samarium impurity is introducad as samarium difluoride SmF

2

and the phosphors are synthesized with successive firing of 6 hr in a stream of pure hydrogen in the temperature range of 800-900℃. The data of X-ray diffraction agree with that of references and standard cards. Using this method

samarium has beon stabilized in the divalent state in SrBeF

4

and BaBeF

4

. But in CaBeF

4

although in the same synthetic conditions

the emission spectrum of divalent samarium has not been observed either. This indicates that the stability of divalent samarium not only depends on the synthetic conditions but also the composition of the matrix. The data of ESCA indicate that with the increase of the radius of substituted cation

the stability of divalent samarium increases. The emission spectra of Sm

2+

and Sm

3+

in MeBeF

4

are presented and briefly discussed. For the spectra of Sm

2+

in SrBeF

4

and BaBeF

4

its excitation peak is due to the transition absorption of

4

f

6

-

4

f

5

d

and the emission peak is due to the transition emission of

5

D

0

-

7

F

7

. The transition emission designations of Sm

3+

in MeBeF4 are due to

4

G

5/2

-

8

H

j

.