Emission spectra from SrB

4

O

7

doped with Dy

2

O

3

and heated in air have been recorded at room temperature.A change in oxidation state from Dy

3+

to Dy

2+

was observed.Optimum production of Dy

2+

ion occurs when the sample is heated in air at about 650℃.Two broad emission bands centered in the vicinity of 550 and 660nm have been observed from the sample under the excitation of 457.9nm.It is suggested that these bands are due to Dy

2+

ion emission from the 5d band into the ground state 4f level(

5

I

8

).Several conditions promoting the reduction of Dy

3+

ion in this matrix are discussed.To aid the reduction of Dy

3+

ion

we have also prepared SrB

4

O

7

doped with Dy

2

O

3

in Ar/H

2

(4%) atmosphere and compared the optical characteristics of Dy

2+

ion in these samples with those from the samples prepared in air.The range of g-element reducibility and stabilization in SrB

4

O

7

has been extended from Tm

2+

[E

0

(Tm

3+

/Tm

2+

)=-2.3V] to Dy

2+

[E

0

(Dy

3+

/Dy

2+

)=-2.6V] in the present work;however

the limit of this facile reduction process has not been determined yet.