Luminescence and Dosimetry Approach in Terbium(iii)-Activated Tungstate Double Perovskite.

A series of tungstate double perovskite Ca3WO6 doped with Tb3+ was prepared by a combustion process using urea as a flux. The crystal structure identification of Ca3WO6:Tb3+ phosphors was done using X-ray diffraction patterns, and a monoclinic structure was discovered. The Fourier transform infrared spectrum of Ca3WO6:Tb3+ displayed characteristic vibrations of tungstate bonds. Under 278 nm excitation, Ca3WO6:Tb3+ exhibited intense downconversion green emission, which corresponded to the 5D4-7FJ (J = 4,5) transitions of Tb3+. The phosphor exhibited the highest photoluminescence (PL) intensity when it was doped with 1 mol% of Tb3+; later intensity quenching appeared to be due to the multipolar interaction at higher dopant concentrations. Moreover, high-quality thermoluminescence (TL) was detected when phosphors were irradiated using beta rays. The effects of Tb3+ concentration and beta dose on TL intensity were the two major aspects studied in detail. The TL intensity demonstrated excellent linear response to the applied range of beta dose. The trap parameters of the studied phosphors were computed by the peak shape approach and glow curve deconvolution. The fading effect on TL intensity was studied by recording the TL glow curves after 1 month of beta irradiation. Obtained results from the PL and TL characterizations showed that the phosphors under study have the potential to be used in lighting displays and in thermoluminescence dosimetry. A luminescent double perovskite Ca3WO6:Tb3+ prepared via a high-temperature combustion route with excellent photoluminescence and thermoluminescence display will make it a multipurpose material that could be used as a display phosphor and a TLD material.image