Radiation-induced defects and their recombination processes in the x-ray storage phosphor BaBr₂:Eu² 

Abstract

The recombination processes in the x-ray storage phosphor BaBr 2 :Eu 2+ were investigated by optical and magneto-optical methods. A structure-sensitive investigation of the defects involved in the recombination processes was performed by detecting the microwave-induced changes in the recombination luminescence in a high magnetic field. F centres as well as V K hole centres are created after x-irradiation at low temperatures. The low-energy recombination band peaking at about 460 nm is due to F-V K centre recombinations, whereas the two high energy bands at 282 and 315 nm are probably due to recombinations of self-trapped excitons.

${\rm Eu}$- or ${\rm Ce}$-Doped Barium Halide Scintillators for X-Ray and $\gamma$-Ray Detections

“…For only a broad band at 550 nm can be seen. The additional bands agree with those of the corresponding undoped crystals [11]. Besides the bands at 420 and 480 nm, the spectrum of shows a weak band at 305 nm which corresponds to the ultraviolet STE band observed in undoped .…”

Europium‐doped barium halide X‐ray scintillators

“…For Eu-doped BaCl 2 and BaBr 2 the Eu 2+ emission dominates the XL spectra. The additional shoulder at 480 nm observed in Eu-doped BaBr 2 has previously been found in undoped BaBr 2 and it has been ascribed to F-V K centre recombination [7]. The 530 nm XL band in Eu-doped BaI 2 , which is even more intense than the Eu 2+ emission at 425 nm, may be caused by the same process.…”

Europium-doped barium halide scintillators for x-ray and γ-ray detections

“…The 450 nm XL found in undoped BaBr 2 has previously been ascribed to F-V K center recombination. 13 The 450 nm band in undoped BaCl 2 and the 530 nm band in BaI 2 might be caused by the same process. We assume that there is an energy transfer mechanism between the F-V K pair and Eu 2+ .…”