Mechanoluminescence, thermoluminescence, photoluminescence studies on Ca3Y2Si3O12:RE(3+) (RE(3+) = Dy(3+) and Eu(3+)) phosphors.

Dy(3+) and Eu(3+) activated Ca3Y2Si3O12 phosphors were synthesized by the solid-state synthesis method. The phosphors were characterized by X-ray diffraction (XRD), mechanoluminescence (ML), thermoluminescence (TL) and photoluminescence (PL) to determine structure and luminescence. For ML glow curves, only one peak was observed, as only one type of luminescence centre was formed during irradiation. The Ca3Y2Si3O12:Dy(3+) TL glow curve showed a single peak at 151.55 °C and the Ca3Y2Si3O12:Eu(3+) TL glow curve peaked at 323 °C with a small peak at 192 °C, indicating that two types of traps were activated. The trapping parameters for both the samples were calculated using Chen's peak shape method. Dy(3+)-activated Ca3Y2Si3O12 showed emission at 482 and 574 nm when excited by a 351 nm excitation wavelength, whereas the Eu(3+)-activated Ca3 Y2Si3O12 phosphor PL emission spectra showed emission peaks at 613 nm, 591 nm, 580 nm when excited at 395 nm wavelength. When excited at 466 nm, prominent emission peaks were observed at their respective positions with very slight shifts.

Experimental and theoretical study of mechanoluminescence and lyoluminescence of Li3 PO4 : RE (RE = Dy and Tb) phosphors.

Li3 PO4 phosphors prepared by solid-state diffusion technique and lyoluminescence (LL) as well as mechanoluminescence (ML) studies are reported. Dy- and Tb-activated phosphors show dosimetric characteristics using LL and ML techniques. The energy levels and hence trapping and detrapping of charge carriers in the material can be studied using ML. Li3 PO4 phosphor can be used in the dosimetric applications for ionizing radiation. By using the LL technique, the LL characteristics of Li3 PO4 may be useful for high radiation doses. We also report a more detailed theoretical understanding of the mechanism of LL and ML.