Luminescence characterization of Ce and Gd doped MgB4O7 phosphors

This paper presents the results of the structural and luminescence characterization of Ce3+ and Gd3+ doped MgB4O7 powders produced by the solid-state synthesis technique. The phase composition of the samples was confirmed by X-ray Diffraction (XRD) method. Morphological characterization using a Scanning Electron Microscope (SEM) revealed a regular surface morphology with spherical/cylindrical grains. The luminescent properties were examined by measuring the RL emission spectra, Optically Stimulated Luminescence (OSL) decay signal, and Thermoluminescence (TL) glow curve. The correlation between luminescence intensity and concentration quenching of the prepared phosphor was investigated. The results show a maximum luminescence efficiency when the synthesis of MgB4O7:Ce,Gd was carried out using contents of 0.1 wt% Ce3+ and 3 wt% Gd3+. The data shows that at the heating rate of 5 °C/s, MgB4O7:Ce0.1%,Gd3% exhibits five TL peaks: two rapidly decaying peaks at about 80 °C and 110 °C, a shoulder peak at 180 °C, a high sensitivity peak at 235 °C TL and another shoulder peak at 320 °C (temperatures are approximate). The step annealing patterns suggest that the origin of the OSL signal is associated with the TL traps located between 180 and 235 °C. The kinetic parameters using various heating rate (VHR) technique, Tm-Tstop assisted extended initial rise method (IRM) and computerized glow curve deconvolution (CGCD) method were obtained and compared. The phosphor showed the dose linearity up to 10 Gy beta dose with a slight supralinearity for higher doses and the minimum detectable dose value of 743.1 ± 11 μGy. Fading and reusability studies of MgB4O7:Ce0.1%,Gd3% further confirmed the phosphor suitability for radiation dosimetry. [Display omitted] •Ce3+ and Gd3+ doped MgB4O7 powder samples were synthesized using the solid-state technique.•The grains with well-defined boundaries were observed following the sintering at 830 °C for 6 h.•MgB4O7 with 3% Gd produced the desired effect on the characteristic 315 nm RL emission band of Gd3+.•OSL response of MgB4O7:Ce0.1%,Gd3% phosphor was found to be slightly linear between 0.1 Gy and 100 Gy.•It appears that the activation energy levels are located between ∼0.77 and 1.57 eV using the Tm-Tstop technique.