Radiation Induced Abnormal Reduction of Eu3+ and Luminescence Properties of NaLi2PO4:Eu (original) (raw)
Related papers
We report the optically stimulated luminescence of Eu 3+ doped NaLi 2 PO 4 synthesized by solid state diffusion method which is crushed and sieved further using Ball milled for different time period (1 to 10 days) with different particle sizes ranging from micro to nano sizes are obtained. Formation of the material was confirmed by XRD analysis and matched peak to peak with JCPDS#80-2110. Scanning electron microscope (SEM) images were used for determining its particle size(s). Optically stimulated luminescence (OSL) characteristics were studied to see the effect of particle size after irradiating with γ-rays from Co 60 source for wide dose range (10 Gy-100 KGy). It was found that OSL sensitivity depends on particle size of the material. Easy method of synthesis, good sensitivity, low fading, good chemical stability, etc. make this OSLD nano phosphor a good candidate for radiation dosimetry using OSL.
NaLi2PO4:Eu3+ based novel luminescent red phosphor
Eu3? doped NaLi2PO4 red luminescent phosphor has been synthesized by solid state reaction and its phase purity has been confirmed by X-ray diffraction analysis. Optical properties of the phosphor have been investigated and the effect of dopant (Eu3?) concentration (0.1–3.0 mol%) has been observed. Excitation spectra of the phosphor NaLi2- PO4:Eu3? show a very efficient absorbance band corresponding to the common allowed transition 7F0 ? 5L6 occurring at 393 nm, while the luminescence spectra exhibit prominent emission peak centered at 702 nm (5D0 ? 7F4) in pure red region. Color purity of this red phosphor has been calculated and found to be around 99.9 %, which is very close to that of commercial red phosphor Y2O3:Eu3?. Luminescence studies of the phosphor show excellent stability with respect to excitation energy. Chromatic investigations have also been performed using emission spectrum and some important chromatic parameters are calculated using CIE-1931 color calculator in order to find potential application of the phosphor.
Synthesis and dosimetry characteristics of a new high sensitivity TLD phosphor NaLi2PO4:Eu3+
A new highly sensitive, low-Z (Zeff z 10.8) TLD phosphor, Eu3þ doped NaLi2PO4, was successfully synthesized via solid state diffusion method. The formation of the single phase compound was confirmed by Powder X-Ray diffraction (PXRD) analysis. Variation of the doping level has shown that the impurity (Eu3þ) concentration for maximum TL sensitivity is 0.5 mol%. Heat treatments given to achieve the high TL sensitivity of this phosphor also showed that it needs to be annealed at 973 K for 1 h. Incorporation of the impurity in the Euþ3 states was confirmed by the PL emission peaks. The TL glow curve consists of a prominent dosimetry peak at around 458 K besides small shoulders on both sides at around 400 and 500 K. The dose response of the phosphor was found to be sub-linear up to 10 Gy of the dose and later it becomes linear till it start saturating beyond 1 kGy. The TL sensitivity of the newly developed NaLi2PO4:Eu3þ phosphor to g radiation from 137Cs (in the linear dose range) was compared to some standard commercially available phosphors, such as, TLD-100, TLD-400, TLD-700H and TLD-900. It was found to be much more sensitive than these phosphors except TLD-700H, which is w2 times more sensitive. Easy method of synthesis, simple glow curve structure, high sensitivity, low fading, wide range of doses and very good reusability make the phosphor a suitable candidate for the TL dosimetry.