A
Sm3+
-doped
normalBa2SinormalO4
phosphor was prepared by high-temperature solid-state reaction. The reduction of
Sm3+
to
Sm2+
was achieved by X-ray irradiation on the as-prepared
normalBa2SinormalO4:normalSm3+
. With the increasing exposure time, the
Sm2+
-luminescence tends to be stronger up to
10h
and then saturated. The
Sm2+
ions with different site symmetries formed in
normalBa2SinormalO4
were observed in the emission spectra due to the
normalD05→normalF07
transition and the decay curves of the
D05
level at various temperatures
(10–300K)
. The
Sm2+
at the different sites in
normalBa2SinormalO4
showed different quenching temperatures. Three crystallographic sites were identified in
normalBa2SinormalO4
below
150K
. However, only one site was left at temperature higher than
190K
. The mechanism involved in the conversion of
Sm3+
to
Sm2+
under X-ray irradiation was discussed on the base of the crystal structure, crystallographic site-distributions, charge compensations, the crystal field strength acting on
Sm2+
, and the defects created by X-ray irradiation. The photostability of the
Sm2+
was evaluated with the photobleaching by monitoring the luminescence due to the
normalD05→normalF07
transitions under the excitation of
488nm
Ar+
laser. The results in this report give some necessary information for its possible applications for optical storage devices.