Thermoluminescent studies of GdAlO3 powders.

The increasing use of thermoluminescence (TL) materials as radiation detectors with application in different areas of ionizing radiation has motivated research on new materials with adequate luminescent characteristics. In this work, experimental results gadolinium aluminate (GdAlO3) analyzed by thermoluminescent phenomenon under beta irradiation effect are studied. To prepare GdAlO3 powders the coprecipitation method was used. TL glow curve and other luminescent characteristics were analyzed using an automatic Lexsig Smart TL/OSL luminescent reader. TL glow curve showed four peaks with three prominent and well-defined peaks centered at 140, 230, and 270 °C. TL response as a function of beta radiation dose was linearity in the range from 1.1 up to 44 Gy. Kinetic parameters such as activation energy (E), frequency factor (s), and order of kinetics after the deconvolution of the TL glow curve were also determined using Chen's peak shape method. Experimental results show GdAlO3 as a potential luminescent host material for TL studies.

Interface behavior of Al2O3/Ti joints produced by liquid state bonding.

In this work we study brazing of Al2O3 to Ti with biocompatibility properties, using a Au-foil as joining element. Al2O3 was produced by sintering of powder at 1550°C. Al2O3 samples were coated with a 2 and 4µm thick of Mo layer and then stacked with Ti. Al2O3-Mo/Au/Ti combinations were joined at 1100°C in vacuum. Successful joining of Mo-Al2O3 to Ti was observed. Interface shows the formation of a homogeneous diffusion zone. Mo diffused inside Au forming a concentration line. Ti3Au and TiAu phases were observed.

Thermal effect on thermoluminescence response of hydroxyapatite.

This paper presents the experimental results of the thermoluminescence (TL) induced by gamma radiation in synthetic hydroxyapatite (HAp) obtained by the precipitation method, using Ca(NO3)2·4H2O and (NH4)2HPO4 and calcined at different temperatures. The structural and morphological characterization was carried out by X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. TL response as a function of gamma radiation dose was in a wide range, where intensity was enhanced in the sample annealed at 900°C, which tricalcium diphosphate (TCP) phase appear. Fading of the TL was also studied.