Rene R. Rocca

TL dating of pottery fragments from four archaeological sites in Taquari Valley, Brazil

Sixty-three pottery fragments from four archaeological sites, numbered RST110, RST101, RST114 and RST114, in the Taquari Valley, vicinity of the city of Lajeado, Rio Grande do Sul state, southern Brazil, have been dated by the thermoluminescence method. Some of them from RST110 and RST101 are as old as 1400–1200 years, whereas those from RST114 and RST107 are younger than 800 years. This result indicates that RST101 and RST110 were peopled earlier than RST114 and RST107. The recent dates found are 302, 295 and 146 years and they are possible, since the first German immigrants who arrived in this region encountered Tupi–Guarani Indians still living there. One interesting result refers to the glow curves of quartz grains RST110, RST101 and RST114 that differ from the glow curves of RST107 quartz grains.

Investigation on luminescence properties of nanocrystalline calcium oxide exposed to beta rays

Nanocrystalline calcium oxide (CaO) is synthesized by solution combustion technique. Structural, TL and OSL properties of CaO are investigated as a function of annealing temperature. XRD pattern of the sample reveal calcium hydroxide of hexagonal phase. Average crystallite size is found to be 25–40 nm. TL glow curve shows single prominent peak at 448 K, 456 K and 453 K for 750, 900 and 1050°C annealed samples respectively. Whereas, 1200°C annealed sample shows four prominent TL glow peaks at 432, 468, 588 and 704 K. TL glow peak shape and position is changed with annealed temperature. In OSL, highest intensity is observed for 1200°C annealed samples. TL kinetic parameters are calculated using computerized glow curve deconvolution analysis.

Effects of Heat Treatments on the Thermoluminescence and Optically Stimulated Luminescence of Nanostructured Aluminate Doped with Rare-Earth and Semi-Metal Chemical Element

© 2012 Tatumi et al., licensee InTech. This is an open access chapter distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Effects of Heat Treatments on the Thermoluminescence and Optically Stimulated Luminescence of Nanostructured Aluminate Doped with Rare-Earth and Semi-Metal Chemical Element

Thermoluminescence and Optical Absorption of Lizardite crystals

Pellets of lizardite crystals (Mg3 [Si,Fe]2O5 (OH)4]) and teflon powder have been investigated to identify the centers related to thermoluminescence (TL) emission. All the Tl peaks are well fitted by using a second order kinetic model and the related trap parameters and activation energy are evaluated. Moreover, the measured optical absorption bands, in the visible and UV ranges, and in the infrared region, are attributed to charge transfer involving Mn and Fe ions and to vibration modes of Mg-O-H groups, respectively