Photoluminescence and thermoluminescence in Dy -, Ce -, and Tb -activated MgB O phosphor for dosimetry application.

Samples of microcrystalline rare earth-doped magnesium borate materials were synthesized via modified solid-state diffusion and were characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. Photoluminescence (PL) results for the MgB O :Dy sample depicts blue emission that resulted from a F - H transition that peaked at 484 nm, which was much stronger than the yellow emission arising due to the F - H transition at 576 nm. From the emission spectra for MgB O :Tb, it seems that at higher concentrations of Tb ion, the green emission becomes strong and directly relates to the energy transfer from the D excited state to the D excited state through a cross-relaxation, whereas the blue emission is suppressed in MgB O phosphors.