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Scintillators, which can emit visible photons under γ- or X-ray excitation, are widely used in radiation detection. Traditional inorganic scintillators usually have some drawbacks, such as hygroscopicity or a high synthesis temperature, and most of them are poisonous. Hence, we report the synthesis of metal iodate scintillators (Eu(IO3)3 and Tb(IO3)3) by a facile hydrothermal reaction that exhibit good radioluminescence (RL) intensity. To further increase the RL intensities, we prepared Eu(IO3)3:xSm and Tb(IO3)3:xGd with stronger RL intensities and higher sensitivities than BaF2 and PbWO4 powders when x = 3%. Furthermore, we obtained scintillating films consisting of Eu(IO3)3:3%Sm and Tb(IO3)3:3%Gd for X-ray imaging. Our Eu(IO3)3:3%Sm and Tb(IO3)3:3%Gd films revealed excellent luminescence under high-energy X-ray excitation and spatial resolutions down to 9 lp mm−1 and 8 lp mm−1, respectively. Thus, these films can be regarded as candidate materials for X-ray imaging. [ABSTRACT FROM AUTHOR]

Semiconductor‐based X‐ray detectors with low detectable thresholds become critical in medical radiography applications. However, their performance is generally limited by intrinsic defects or unresolved issues of materials, and developing a novel scintillation semiconductor for low‐dose X‐ray detection is a highly urgent objective. Herein, a high‐quality rare‐earth iodate Tm(IO3)3 single crystal grown through low‐cost solution processing is reported with a wide bandgap of 4.1 eV and a large atomic number of 53.2. The roles of IO and TmO groups for charge transport in the Tm(IO3)3 are revealed with the structural difference between the [101] and [1¯01]$[{\bar{1}}01]$ crystal orientations. Based on anisotropic responses of material properties and detection performances, it is found that the [1¯01${\bar{1}}01$] orientation, the path with fewer IO groups, achieves a high resistivity of 1.02 × 1011 Ω cm. Consequently, a single‐crystal detector exhibits a low dark current and small baseline drifting due to the wide bandgap, high resistivity and less ion migration of Tm(IO3)3, resulting in a low detection limit of 85.2 nGyair s−1. An excellent X‐ray imaging performance with a high sensitivity of 4406.6 µC Gyair−1 cm−2 is also shown in the Tm(IO3)3 device. These findings provide a new material design perspective for high‐performance X‐ray imaging applications. [ABSTRACT FROM AUTHOR]

Materials exhibiting mechanoluminescence (ML) are a class of smart materials capable of mechanical-to-light energy conversion. Thus, ML materials have been widely used in various electronic applications such as smart sensors, security systems, human–machine interfaces, and energy harvesting systems. Herein, we report a centrosymmetric ML semiconductor host material family MGa2S4 (M = Ca, Sr), which features in-layered structures constructed with unique distorted bi-tetrahedral [Ga2S2S4/2] lattice units. It exhibited similar structural characteristics to the well-known ML semiconductor host ZnS. Remarkably, the lanthanide ions of 5d → 4f transition-activated hosts showed sensitive and high ML luminance under natural lighting upon mechanical stimulation; thus, an efficient mechanical-to-light energy conversion of a self-powered display was achieved. Moreover, because of structural distortion and strain-gradient-induced electrical polarization in the ML host material upon mechanical stimulation, a ML mechanism based on the synergy effect between local electronic polarization and flexoelectricity was proposed. This study facilitates a deeper understanding of the relationship between the structure and underlying ML, and promotes further development of ML-material-based products and technologies. [ABSTRACT FROM AUTHOR]

Magneto-optical materials with high Verdet constants at high extinction ratios are desirable for the Faraday isolators. However, current terbium-based crystals have encountered several issues, such as low Verdet constants (TGG crystals), difficult growth (TSAG crystals), and low utilization of raw materials, which limit the development of the Faraday isolators. Here, R 0.0025 TSAG (R= Pr, Ho, Dy, Eu) transparent ceramics are prepared. The ceramics exhibit high optical transparency above 74.0% in the 525–1565 nm range and a high relative density of 98.9%. In particular, the transmittance of R 0.0025 TSAG ceramics at 1064 nm is approximately 81.6%, 81.6%, 79.8%, and 80.6%, respectively. The Verdet constants of R 0.0025 TSAG ceramics at the measurement wavelength are greater than those of the TSAG ceramic. The compelling magneto-optical performance of the Dy 0.0025 TSAG ceramic includes a high Verdet constant of 161.8 ± 3 rad·m−1·T−1 at 635 nm. The Verdet constant of the Dy 0.0025 TSAG ceramic is still superior to that of TSAG ceramic in the same temperature range. The extinction ratios of the R 0.0025 TSAG (R= Pr, Ho, Dy) ceramics exceed 40 dB. The figure of merit points out the superior characteristics of R 0.0025 TSAG ceramics. Moreover, R 0.0025 TSAG (R= Pr, Ho, Dy) ceramics with a thickness above the centimeter level are successfully prepared. This work indicates that the Dy 0.0025 TSAG ceramic can promote the miniaturization of magneto-optical isolators and can be applied in high-power lasers. • (Tb 0.9975 R 0.0025) 3 Sc 2 Al 3 O 12 (R= Pr, Ho, Dy, Eu) transparent ceramics were synthesized and characterized. • The Verdet constants of R-TSAG ceramics at the measurement wavelength are greater than that of TSAG ceramic. • The values of extinction ratio for R-TSAG (R= Pr, Ho, Dy) ceramics exceed 40 dB. [ABSTRACT FROM AUTHOR]

Scintillators play a vital role in high-energy physics, medical imaging, security inspection, etc. Here, we designed and prepared a highly efficient scintillator of Ce,Tb-codoped LiLuF 4 , which was synthesized by a hydrothermal method using low-cost raw materials. The microcrystalline scintillator exhibits the strong luminescence of rare earth ion, which has a characteristic green fluorescence emission with a quantum yield of 71.59%. This material has a strong X-ray response, superior light output (16,509 ph/MeV), excellent ray cut-off capability and absolute stability. Based on micron-level powdered compounds, we used direct coating to manufacture a scintillation film with a size of 5.5 cm × 8.0 cm for X-ray imaging testing. The imaging test shows that the highly stable scintillation film not only has a spatial resolution capability of more than 10.0 LP/mm but also has great potential to be prepared as a flexible scintillator, which exhibited excellent performance as an potential scintillation detection material. Tetragonal LLF:Ce,Tb MCs exhibit bright and sensitive radioluminescence with the energy transfer process between rare earth ions, and its composite film can provide a decent spatial resolution for X-ray imaging applications. [Display omitted] • Lu element was used instead of Y element to improve the scintillation property of the material. • Ce ion sensitizing Tb ion strategy was adopted to improve the radiation light output of the material. • A large area scintillation film with transmittance of 79.92% was successfully prepared by direct coating method. • The spatial resolution of the scintillation film for radiation detection is more than 10.0 LP/mm. [ABSTRACT FROM AUTHOR]