Scintillation response of Y3Al5O12:Pr3+ single crystal scintillators
Introduction
Single crystal scintillators are widely used for the detection of ionizing radiation in nuclear and high energy physics, modern medical imaging, space exploration and industry. The fast and efficient 5d → 4f luminescence of Ce3+ makes it an effective emission center in scintillator applications. Therefore, Ce3+-doped inorganic scintillators such as e.g., Y3Al5O12:Ce (YAG:Ce) (Moszynski et al., 1994), Lu2SiO5 (LSO:Ce) (Melcher and Schweitzer, 1992), (Lu,Y)2SiO5:Ce (LYSO:Ce) (Cooke et al., 2000), Lu3Al5O12:Ce (LuAG:Ce) (Nikl et al., 2000) and LuYAlO3:Ce (LuYAP:Ce) (Drozdowski et al., 2006) have been intensively studied.
Pr3+-doped Lu3Al5O12 (LuAG:Pr) single crystal was reported as a fast and efficient scintillator (Nikl et al., 2005; Ogino et al., 2006). Pr3+-doped Y3Al5O12 (YAG:Pr) single crystal with a high light yield of about 300% with respect to Bi4Ge3O12(BGO) and a short decay time of about 18 ns was reported (Drozdowski et al., 2005). Recently, YAG:Pr with a prospective light yield comparable to LuAG:Pr (about 160% of BGO) and a fast scintillation response dominated by a 17 ns decay time was also reported (Pejchal et al., 2009).
In this work we studied a set of YAG:Pr crystals grown by the Czochralski method as for their photoluminescence (PL), radioluminescence (RL) spectra and PL decay. Furthermore, pulse height spectra were performed to evaluate light yield (LY), its non-proportionality and energy resolution. The estimated photofraction in the pulse height spectra of 320 and 662 keV γ-rays was also determined and compared with the ratio of the cross-sections for the photoelectric effect to the total one (WinXCOM program).
Section snippets
Experimental
YAG:Pr single crystals grown in the same batch by Czochralski method from 5N raw Y2O3, Al2O3 powders and 4N Pr6O11 one were produced by Crytur Ltd. in Czech Republic. Pr concentration of 0.16, 0.33, and 0.65 mol% in the crystal was determined by the wavelength dispersive X-ray fluorescence (WDX) method using RFA Philips PW 2400 apparatus at L-alpha line of Pr. For quantitative measurement the calibration set of mixed Y2O3, Al2O3 a Pr6O11 powders was prepared. We estimate the detection limit at
Luminescence characteristics
In Fig. 1 the PL spectra of YAG:Pr crystals are given together with the absorption spectrum for 0.16% Pr sample in the inset. The absorption bands at 240 and 290 nm can be attributed to the two lowest 4f(3H4) → 5d2,1 transitions of Pr3+. Week Pr3+4f → 4f transitions between 450 and 490 nm (3H4 → 3Px,1I6) and around 609 nm (3H4 → 1D2) were also observed in the absorption spectrum. Excitation within the 4f → 5d1 absorption band results in the dominant emission at 318 nm with a shoulder at 380 nm,
Conclusion
The luminescence and scintillation properties of YAG:Pr crystals grown by the Czochralski method were investigated. YAG:Pr exhibits a dominant emission peak at 318 nm with a shoulder at 380 nm under UV and X-ray excitations with a fast PL decay time of about 15 ns based on 5d1 → 4f transition of Pr3+. It shows integral scintillation efficiency of about 400% of that of the BGO. The YAG:Pr (0.33%) sample exhibits a high LY of 15,600 ph/MeV and a good energy resolution of 6.4% in a pulse height
Acknowledgments
This work was supported by the National Research University Project of Thailand's Office of the Higher Education Commission. Financial support of Czech GACR P204/12/0805 project is also gratefully acknowledged.
References (15)
- et al.
Comparison of Lu3Al5O12:Pr3+ and Bi4Ge3O12 scintillators for gamma-ray detection
Radiat. Meas.
(2012) - et al.
Thermoluminescence and scintillation of praseodymium-activated Y3Al5O12 and LuAlO3 crystals
J. Cryst. Growth
(2005) - et al.
Scintillation properties of LuAP and LuYAP crystals activated with cerium and molybdenum
Nucl. Instrum. Methods Phys. Res. A
(2006) - et al.
WinXCom – a program for calculating X-ray attenuation coefficients
Rad. Phys. Chem.
(2004) - et al.
Properties of the YAG:Ce scintillator
Nucl. Instrum. Methods Phys. Res. A
(1994) - et al.
Intrinsic energy resolution of NaI(Tl)
Nucl. Instrum. Methods Phys. Res. A
(2002) - et al.
Scintillation characteristics of Pr-doped Lu3Al5O12 single crystals
J. Cryst. Growth
(2006)
Cited by (17)
Electron and photon responses of CWO scintillation crystal
2021, Radiation Physics and ChemistryInfluence of the ratio of rare earth oxyorthosilicate R<inf>2</inf>SiO<inf>5</inf> (R = La, Y) hosts on the structure and optical properties of co-doped Pr<sup>3+</sup> /Dy<sup>3+</sup> phosphors
2020, Ceramics InternationalCitation Excerpt :Defined as hypersensitive, the yellow emission, which is an electric dipole transition, is highly sensitive to the crystal field around Dy3+ ions. Differently, the bluish emission is a magnetic dipole transition and hardly varies with the crystal field around Dy3+ ions [9]. The variation in the molar ratio of La and Y in La2-xYxSiO5 (x = 0, 0.5, 1, 1.5 and 2) host will result in the unit cell variation of the host and hence tuning of the crystal field strength.
Light yield nonproportionality, intrinsic resolution and α/γ ratio of oxide single crystal scintillators
2019, Radiation MeasurementsCitation Excerpt :The LY values of LuAG:Pr and YAG:Pr were reported about 16,400 ph/MeV (Yanagida et al., 2011) and 15,610 ph/MeV (Sreebunpeng et al., 2013), respectively. Moreover, both crystals exhibited very good energy resolution of 4.6–6.6% at 662 keV γ rays and very good nonproportionality of LY higher than 90% (Drozdowski et al., 2008; Sreebunpeng et al., 2013). Recently, Gd3Al5−xGaxO12:Ce (GAGG:Ce) crystal shows extremely high LY value up to 58,000 ph/MeV and energy resolution of 6.8% (Kamada et al., 2014; Sakthong et al., 2013).
Suppression of the slow scintillation component of Pr:Lu <inf>3</inf> Al <inf>5</inf> O <inf>12</inf> transparent ceramics by increasing Pr concentration
2019, Journal of LuminescenceCitation Excerpt :The intensity of 4f–4f emission between 400 and 700 nm decreases with increasing Pr concentration, especially for the 610 nm (1D2 -3H4) emission. It is caused by the concentration quenching which has been investigated in Pr:YAG [32]. Fig. 4 shows the fluorescence decay curves of the Pr3+ 5d–4f emission of Pr:LuAG ceramics with different doping concentrations under excitation by the 266.6 nm pulse light.