New Intrinsic Scintillator with Large Effective Atomic Number: Tl2HfCl6 and Tl2ZrCl6 Crystals for X-ray and Gamma-ray Detections

Abstract

We report on the photoluminescence and scintillation characterizations of new Tl 2 HfCl 6 and Tl 2 ZrCl 6 crystalline scintillators grown by the vertical Bridgman-Stockbarger method. Both Tl 2 HfCl 6 and Tl 2 ZrCl 6 crystals showed an intrinsic emission band peak at 450-470 nm under UV light and X-ray excitations. The scintillation light yields of Tl 2 HfCl 6 and Tl 2 ZrCl 6 reach 24200 and 50800 photons/MeV, respectively. Their energy resolutions at 662 keV are 17.7% for Tl 2 HfCl 6 and 5.6% for Tl 2 ZrCl 6. The scintillation decay time values of Tl 2 HfCl 6 are 288 and 6340 ns; meanwhile, those of Tl 2 ZrCl 6 are 696 and 2360 ns.

Comparative Studies of Scintillation Properties of Tl-based Crystals

“…Because TlMgCl 3 and Tl 2 ZrCl 6 showed excellent energy resolution, the escape peak of Tl was clearly observed, and these results were consistent with pioneering works. (31,33) Table 1 summarizes the scintillation light yield determined by taking into account the quantum efficiency of PMT and energy resolution at 662 keV. The light yield of Tl 2 ZrCl 6 was higher than that reported previously, (33) which could be attributed to the sample condition or crystal quality.…”

“…(31,33) Table 1 summarizes the scintillation light yield determined by taking into account the quantum efficiency of PMT and energy resolution at 662 keV. The light yield of Tl 2 ZrCl 6 was higher than that reported previously, (33) which could be attributed to the sample condition or crystal quality. Although the energy resolution of TlMgCl 3 was worse than that described in a previous report, (31) it would be consistent within a large uncertainty (fitting error).…”

“…(22)(23)(24) Among such halide materials, Tl-based crystalline materials have shown excellent scintillation properties such as high light yield and energy resolution. (31)(32)(33)(34)(35)(36) Although the R&D of scintillators of the emission center doping type is the recent trend, (37)(38)(39) these Tl-based scintillators can emit sufficient scintillation photons via intrinsic luminescence. In addition to their efficient scintillation properties, a high effective atomic number owing to Tl can be expected, and Tl-based scintillators can be potentially attractive for use as γ-ray scintillation detectors.…”

“…In this work, we investigate Tl-based scintillators such as Tl 2 ZrCl 6 , TlMgCl 3 , TlCdCl 3 , TlSrCl 3 , and TlBaCl 3 focusing on their γ-ray detection properties. Among them, Tl 2 ZrCl 6 , (33) TlMgCl 3 , (31) and TlCdCl 3 (32) have already been investigated extensively, but TlSrCl 3 and TlBaCl 3 have not been investigated yet. The aim of this work is to compare the pulse height spectroscopic properties of these newly developed Tl-based scintillators.…”

Scintillation and Dosimetric Properties of Monocrystalline and Polycrystalline Li2B4O7

“…(7)(8)(9)(10)(11) These scintillators are used for medical imaging, (4) nondestructive inspection, (12) and well logging. (13,14) Although many types of scintillator have been reported, it is still attractive to develop novel scintillators with higher light yields (15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26) and shorter decay times. (27,28) In the radiation dosimetry technique, personal dosimeters are made of dosimetric materials that are mainly solid-state storage phosphors.…”