Synthesis and characterization of flower-like Al₂O₃:C for optically stimulated luminescence (OSL) dosimeter

Abstract

Growth in radiation diagnosis and therapy drives personal radiation dosimeters for physical and radiological protection control. Nevertheless, OSL (optically stimulated luminescence) personal dosimeters in Thailand are all imported. In this work, the particulate and flower-like structure of carbon-doped alpha aluminum oxide polycrystal (α-Al2O3:C) with the various carbon dopants (0.1% and 1 %) were studied as a detector in the OSL personal dosimeter. The particulate powder was prepared by alumina powder (295 nm). The flower-like structure α-Al2O3:C was prepared by boehmite precursors, synthesizing from aluminum sulfate via the low-cost and low-temperature hydrothermal method and sucrose as carbon sources. The crystalline structure was identified by x-ray diffraction (XRD). The chemical properties and oxygen vacancies were investigated by Fourier-transform infrared spectroscopy (FTIR) and x-ray photoelectron spectroscopy (XPS). The size of as-prepared flower-like structure α-Al2O3: C was 2–3 μm confirmed by scanning electron microscopy (SEM). The alumina precursors and carbon dopants affected electron trapping states, morphologies, and OSL outputs. This finding successfully proved that the flower-like α-Al2O3 derived from boehmite precursor exhibits excellent OSL sensitivities to beta irradiation (better than that of the particulate power of α-Al2O3: C) and responded linearly in the range of 0–80 kGy.

Lowering the synthesis temperature of α‐Al2O3 by increasing the content of pentacoordinate aluminum in the precursors

“…This shift occurs because the ball‐milled powder initiates the transformation into α‐Al 2 O 3 after 600°C, and the main factor causing a decrease in specific surface area is the transformation of the cubic close‐packed structure in the transitional alumina to the hexagonal close‐packed structure in α‐Al 2 O 3 . In the range of 400–1000 cm −1 , a broad absorption band characteristic of alumina is evident and a typical α‐Al 2 O 3 absorption band appeared in the ball‐milled powder at 800°C 43 . The intensity of this absorption band between 400 and 1000 cm −1 consistently remains higher in the ball‐milled powder compared to the no ball‐milled one.…”