Er-Doped Mg 4 Ta 2 O 9 Single-Crystal Scintillators Emitting Near-Infrared Photons for High-Dose Field Monitoring.

Mg₄Ta₂O₉ single crystals doped with 0.01, 0.1, and 1% Er were grown using the floating zone method, and their photoluminescence and scintillation properties were studied. X-ray diffraction analysis confirmed that all samples had a hexagonal structure of Mg₄Ta₂O₉. The samples showed that the emission peak at 1550 nm was due to 4f−4f transitions of Er³⁺ ions, with quantum yields of 32.9, 46.6, and 18.0% for 0.01, 0.1, and 1% doping concentrations, respectively. All samples showed scintillation with a broad emission band at 350 nm due to charge transfer from Ta⁵⁺ to O²⁻ ions and emission peak at 1550 nm due to 4f−4f transition of Er³⁺ ions. The dose rate response functions showed that the detection limit for all samples was 0.06 Gy/h for scintillation detector applications. [ABSTRACT FROM AUTHOR]