Abstract
A translucent Gd2O2S:Pr ceramic scintillator with an in-line transmittance of ~31% at 512 nm was successfully fabricated by argon-controlled sintering. The starting precipitation precursor was obtained by a chemical precipitation route at 80 °C using ammonia solution as the precipitate, followed by reduction at 1000 °C under flowing hydrogen to produce a sphere-like Gd2O2S:Pr powder with an average particle size of ~95 nm. The Gd2O2S:Pr phosphor particle exhibits the characteristic green emission from 3P0,1→3H4 transitions of Pr3+ at 512 nm upon UV excitation into a broad excitation band at 285–335 nm arising from 4f2→4f5d transition of Pr3+. Increasing Pr3+ concentrations induce two redshifts for the two band centers of 4f2→4f5d transition and lattice absorption on photoluminescence excitation spectra. The optimum concentration of Pr3+ is 0.5 at.%, and the luminescence quenching type is dominated by exchange interaction. The X-ray excited luminescence spectrum of the Gd2O2S:Pr ceramic is similar to the photoluminescence behavior of its particle. The phosphor powder and the ceramic scintillator have similar lifetimes of 2.93–2.99 μs, while the bulk material has rather higher external quantum efficiency (~37.8%) than the powder form (~27.2%).
Highlights
Scintillation materials convert the radiation of high-energy rays (X-rays or gamma rays) into visible light and are extensively applied in various fields such as safety inspection, high energy physics, nuclear medicine, and industrial non-destructive testing [1,2,3,4,5,6]
A ceramic scintillator is superior to a single crystal due to its low cost, short production cycle, large-size production, as well as high dopant concentration with a homogeneous mixture at the molecular level [6,7,8,9]
Nanocrystalline Gd2O2S:Pr powder was obtained by a reduction reaction under a hydrogen atmosphere at 1000 ◦C from its precipitation precursor prepared by a direct precipitation method, with which translucent Gd2O2S:Pr ceramic was successfully fabricated by pressureless sintering under a protective argon atmosphere
Summary
Scintillation materials convert the radiation of high-energy rays (X-rays or gamma rays) into visible light and are extensively applied in various fields such as safety inspection, high energy physics, nuclear medicine, and industrial non-destructive testing [1,2,3,4,5,6]. Scintillators can be divided into solid, liquid, and gaseous states, among which solid inorganic scintillators, as the most widely used materials, include single crystals and polycrystalline ceramics. Solid-state Gd2O2S (GOS) has excellent chemical and physical characteristics, such as high melting point (2070 ◦C), high density (7.43 g/cm3), high X-ray attenuation coefficient (~52 cm−1 at 70 keV), wide band gap (4.6–4.8 eV), favorable chemical durability, low phonon energy, low crystal symmetry, and low toxicity, which make it a promising host material for luminescence and scintillation applications [10,11]. Nanocrystalline Gd2O2S:Pr powder was obtained by a reduction reaction under a hydrogen atmosphere at 1000 ◦C from its precipitation precursor prepared by a direct precipitation method, with which translucent Gd2O2S:Pr ceramic was successfully fabricated by pressureless sintering under a protective argon atmosphere. The luminescence and scintillation properties of both the Gd2O2S:Pr phosphor and ceramic were studied in detail
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
