Melt-preparation of organic–inorganic Mn-based halide transparent ceramic scintillators for high-resolution X-ray imaging†

Abstract

High-quality and large-size crystals are ideal scintillation screens to achieve high-resolution X-ray imaging. However, it is difficult to obtain large-size scintillation crystals due to the limitations of crystal growth technology. Here, organic–inorganic hybrid Mn-based single crystals (TBP₂MnBr₄, TBP = tetrabutylphosphonium) exhibit a high decomposition temperature (295 °C) and the TBP₂MnBr₄-melt has a low condensation point (48.75 °C), such a wide interval is of benefit to the melt processing method for preparing scintillation screens. The TBP₂MnBr₄-melt exhibits a low viscosity (η(T_m) = 238 mPa s) and flow activation energy (E_a = 10.754 kJ mol⁻¹) making it easy to crystallize. It is worth noting that the low condensation point (T_c) of the TBP₂MnBr₄-melt is slightly higher than room temperature, and this narrow temperature interval can limit the rapid nucleation and growth of the crystals, allowing them to slowly crystallize into transparent ceramics (TC). Circular TBP₂MnBr₄-TC with a size of Φ 11.5 cm can be easily fabricated, which exhibits high optical transmittance, for realizing high-resolution (16 lp mm⁻¹) X-ray imaging. This work brings a new strategy for preparing scintillation screens, as well as promoting the development of TC scintillators for X-ray imaging.