Abstract:
Today, BaFBr crystals activated by europium ions are used as detectors that store absorbed
energy in metastable centers. In these materials, the image created by X-ray irradiation remains stable
in the dark for long periods at room temperature. As a result, memory image plates are created,
and they are extended to other types of ionizing radiation as well. Despite significant progress
towards X-ray storage and readout of information, the mechanisms of these processes have not been
fully identified to date, which has hindered the efficiency of this class of phosphors. In this study,
using photoluminescence (PL), optical absorption (OA), Raman spectroscopy (RS), and atomic force
microscopy (AFM), the luminescence of oxygen vacancy defects to BaFBr crystals irradiated with
147 MeV 84Kr and 24.5 MeV 14N ions at 300 K to fluences (1010–1014) ion/cm2 was investigated.
BaFBr crystals were grown by the Shteber method on a special device. Energy-dispersive X-ray
spectroscopy (EDX) analysis revealed the presence of Ba, Br, F, and O. The effect of oxygen impurities
present in the studied crystals was considered. The analysis of the complex PL band, depending
on the fluence and type of ions, showed the formation of three types of oxygen vacancy defects.
Macrodefects (tracks) and aggregates significantly influence the luminescence of oxygen vacancy
defects. The creation of hillocks and tracks in BaFBr crystals irradiated with 147 MeV 84Kr ions is
shown for the first time. Raman spectra analysis confirmed that BaFBr crystals were amorphized by
147 MeV 84Kr ions due to track overlap, in contrast to samples irradiated with 24.5 MeV 14N ions.
Raman and absorption spectra demonstrated the formation of hole and electron aggregate centers
upon swift heavy ions irradiation.
