Thermoluminescence properties of TiO₂ nanopowder

Titanium oxide (TiO₂)-based ceramics have many desirable and potential applications. Their mechanical properties are strongly affected by composition and microstructure, and can thus be tailored. The optical properties of TiO₂ are useful, being colorless, transparent, and possessing a high refractive index. These properties and the ability to tailor the structure make TiO₂-based ceramics suitable for a wide range of applications. Interest in titanium oxide-based ceramics has increased considerably in recent years as possible thermoluminescence (TL) dosimeters which could be used in a wide variety of research activities and applications of ionizing radiation dosimetry. The aim of this work is to investigate some dosimetric properties of manganese doped titanium oxide (TiO₂ : Mn) nanopowder concerning the TL phenomenon related to its structural, morphological, and luminescent characteristics. Powder of TiO₂ : Mn was prepared using a co-precipitation method from titanium oxysulfate-sulfuric acid complex (TiOSO₄ × H₂ SO₄ × H₂ O) and manganese (II) chloride · 6 H₂ O. Formation of the compound was confirmed by studying the X-ray diffraction patterns. Diffraction patterns obtained suggested a mixture of anatase and rutile structure of the TiO₂ powder analyzed. Assuming the particles are stress-free, the size was estimated from a single diffraction peak using Scherrer's equation. Powder with the average nanopolycrystalline sizes from 10 nm up to about 80 nm was obtained. The glow curve of TiO₂ : Mn nanopowder exposed to gamma radiation exhibited one main peak centered at 240 ^{{ring operator}} C and a lower intensity peak at about 258 ^{{ring operator}} C. The intensity of the main peak increases as the dose increases. TL glow curve intensity of TiO₂ : Mn powder submitted to 1000 ^{{ring operator}} C was found to be more intense than that of the amorphous material, with the intensity increasing with the increase of crystallization temperature.