Phase diagram of BaI2-LuI3 system and growth of BaI2/LuI3 eutectic scintillator

• Published in: Journal of crystal growth 2020-04, Vol.536, p.125573, Article 125573
• Main Authors: Origuchi, Kazuya, Yokota, Yuui, Kral, Robert, Yoshino, Masao, Yamaji, Akihiro, Toyoda, Satoshi, Sato, Hiroki, Ohashi, Yuji, Kurosawa, Shunsuke, Kamada, Kei, Yoshikawa, Akira
• Format: Article
• Language: English
• Subjects: A1. Eutectics; A1. Phase diagrams; B3. Scintillators; Bridgman method; Cerium; Crystal growth; Differential scanning calorimetry; Phase diagrams; Scintillation counters; X ray powder diffraction; X-ray diffraction
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2020.125573

•Phase diagram of BaI2-LuI3 system was created and it was eutectic type diagram.•BaI2-LuI3 system had an eutectic point around 77.5 mol%BaI2/22.5 mol%LuI3.•BaI2/LuI3 eutectic crystal and Ce-doped BaI2/LuI3 eutectic scintillator were grown.•The BaI2/LuI3 eutectic crystal was composed of LuI3 rod phase and BaI2 matrix phase. The phase diagram of the BaI2-LuI3 system was created using powder X-ray diffraction (XRD) and differential scanning calorimetry (DSC) analysis, and a eutectic scintillator crystal was grown by the halide-vertical bridgman (H-VB) method. The results of XRD patterns and DSC curves showed that the phase diagram of the BaI2-LuI3 system had a eutectic point around 77.5 mol% BaI2/22.5 mol% LuI3, and no new compound was generated from BaI2 and LuI3. The 77.5 mol% BaI2/22.5 mol% LuI3 eutectic crystal was composed of BaI2 in rod phase and LuI3 in matrix phase. In addition, the Ce-doped 77.5 mol% BaI2/22.5 mol% LuI3 specimen showed emission peaks originating from 5d–4f transition of Ce3+ ion in the X-ray radioluminescence (XRL) spectrum and the decay time under γ-ray irradiation was approximately 38 ns.