EPR study of Ce3+ ions in lutetium silicate scintillators Lu2Si2O7 and Lu2SiO5

An overview of recognized structural defects, impurities and related trapping levels and their role in the scintillation mechanism is provided and discussed in single crystal materials belonging to tungstate, Ce‐ or Pr‐doped aluminum perovskite, garnet and finally to Ce‐doped silicate scintillators. New achievements and open problems in deeper understanding of electron and hole self‐trapping phenomena and of the nature of defects in the crystal structure and their ability to localize migrating charge carriers are indicated. Fast optical ceramics and nanocomposite materials are pointed out as possible future advanced scintillators. Such novel technologies can in principle explore materials which are not available in the bulk single crystal form, but their figure‐of‐merit is dramatically dependent on the surface‐interface defect states and related trapping and nonradiative recombination phenomena. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

show abstract

“…On the other hand, the composite emission peaking at 460 nm, detected well only below 80 K, was ascribed to the "Ce 2 " center. [133].…”

Section: Orthosilicate Single Crystalsmentioning

confidence: 99%

Complex oxide scintillators: Material defects and scintillation performance

Nikl¹,

Laguta

Vedda

2008

Physica Status Solidi (b)

195

106

View full text Add to dashboard Cite

show abstract

“…Today the main scintillating materials for medical imaging are 8 Gd 2 O 2 S:Pr,Ce,F [1], (Y,Gd)O 3 :Eu,Pr [2] and CdWO 4 [3,4] for X-ray Computed 9 Tomography (CT) whereas BGO (Bi 4 Ge 3 O 12 ) [5,6], NaI:Tl [7], LYSO 10 ((Lu,Y)SiO 5 :Ce 3+ ) [8,9] and LPS (Lu 2 Si 2 O 7 ) [10,11,12] are often used for Positron 11…”

Section: Introduction 1mentioning

confidence: 99%

Improved scintillation time response in (Lu_0.5Gd_0.5)₂O₃ : Eu³⁺ compared with Lu₂O₃ : Eu³⁺ transparent ceramics

Rétot¹,

Blahuta²,

Bessière³

et al. 2011

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

The scintillation properties of two sesquioxides ceramics Lu2O3 : Eu3+ and (Lu0.5Gd0.5)2O3 : Eu3+ were studied. Both ceramics present comparable transparency and light yield whereas (Lu0.5Gd0.5)2O3 : Eu3+ showed an order of magnitude reduced afterglow in the 3–300 ms range. A thorough study of the location and behaviour of Eu3+ dopant ions at C2 and S6 sites of Lu2O3 and (Lu0.5Gd0.5)2O3 structures was carried out with low-temperature selective excitation of Eu3+. This revealed that (i) at both C2 and S6 sites, Eu3+ 4f–4f lifetime is shorter in (Lu0.5Gd0.5)2O3 : Eu3+ than in Lu2O3 : Eu3+, (ii) the host matrix (Lu0.5Gd0.5)2O3 as compared with Lu2O3 favours the location of Eu3+ at C2 site. As decay times of Eu3+ in C2 and S6 sites are 1.0 ms and 3.8 ms, respectively, the preferred occupation of C2 in (Lu0.5Gd0.5)2O3 : Eu3+ implies a much shorter decay time for (Lu0.5Gd0.5)2O3 : Eu3+ in the 3–20 ms range. Reduction of afterglow in the 20–300 ms range is illustrated by thermally stimulated luminescence peaks presenting a highly reduced intensity for (Lu0.5Gd0.5)2O3 : Eu3+ compared with Lu2O3 : Eu3+ implying reduced charge trapping defects in (Lu0.5Gd0.5)2O3 : Eu3+ ceramics.

show abstract

“…The occurrence of two Ce 3+ luminescent centers in LSO, YSO, and GSO has been established in the early 1990's [56] given to two Lu or Gd sites in the structure mentioned above. EPR study determined [74] that about 95% of Ce 3+ centers is located at bigger 7-coordinated site in LSO. The onset of excited state ionization of Ce 3+ centers around room temperature was found by classical photoconductivity studies [75] and further described in detail by purely optical methods [76].…”

Section: Growth Of Lumentioning

confidence: 99%

Czochralski Growth and Properties of Scintillating Crystals

2013

View full text Add to dashboard Cite

The Czochralski method is one of the very few melt growth techniques that are industry friendly when considering the combination of quality, dimensions, and cost of the produced crystals suitable for their commercialization in scintillation detectors. This method is one of the oldest and most developed crystal growth processes regarding an adequate understanding the physical phenomena observed during solidication process and its practical expansion especially in the industrial scale production. It allows controllable formation of single-crystalline cylindrical ingots of various inorganic scintillation materials. The review summarizes recent progress on the Czochralski growth of a number of scintillation materials. The oxide crystals are mainly considered including the Ce and Pr--doped RE3Al5O12, RE = Y, Lu, aluminum garnets and newly discovered ultraecient Ce-doped Gd3(Ga,Al)5O12 multicomponent garnet, high density PbWO4 and CdWO4 tungstates, Ce-doped RE2SiO5, RE = Y, Gd, Lu, oxyorthosilicates and (Y,Lu)AlO3 aluminum perovskites and nally the classical Bi4Ge3O12 scintillator. Additionally, the details of the growth of other practically important non-oxide crystals, namely the Ce and Eu-doped LiCaAlF6 neutron and ultraecient Ce-doped LaBr3 scintillators, are discussed. The potential of novel micro-pulling down growth method is briey described in the combinatorial search for new scintillator materials. Selected luminescence and scintillation characteristics including the spectra and decay kinetics, light yield and radiation resistance are also illustrated and overviewed.

show abstract

EPR study of Ce3+ ions in lutetium silicate scintillators Lu2Si2O7 and Lu2SiO5

Cited by 113 publications

References 26 publications

Complex oxide scintillators: Material defects and scintillation performance

Complex oxide scintillators: Material defects and scintillation performance

Improved scintillation time response in (Lu_0.5Gd_0.5)₂O₃ : Eu³⁺ compared with Lu₂O₃ : Eu³⁺ transparent ceramics

Czochralski Growth and Properties of Scintillating Crystals

Contact Info

Product

Resources

About

EPR study of Ce3+ ions in lutetium silicate scintillators Lu2Si2O7 and Lu2SiO5

Cited by 113 publications

References 26 publications

Complex oxide scintillators: Material defects and scintillation performance

Complex oxide scintillators: Material defects and scintillation performance

Improved scintillation time response in (Lu0.5Gd0.5)2O3 : Eu3+ compared with Lu2O3 : Eu3+ transparent ceramics

Czochralski Growth and Properties of Scintillating Crystals

Contact Info

Product

Resources

About

Improved scintillation time response in (Lu_0.5Gd_0.5)₂O₃ : Eu³⁺ compared with Lu₂O₃ : Eu³⁺ transparent ceramics