E.P. Zavala

IBA analysis of a possible therapeutic ancient tooth inlay

Abstract Five pre-Columbian human teeth from the same skeleton found during excavation in an ancient ceremonial center in Mexico, have been analyzed by two conventional Ion Beam Analysis (IBA) techniques: PIXE and 4 He RBS. The anthropologists have estimated that the skeleton is about 2000 years old. X-ray radiography studies of one of these teeth have revealed that they contain an inlay in the tooth crown. The IBA methods have been used to study the inlay materials and also the tooth enamel. The IBA studies show that the tooth inlay materials have almost the same atomic composition as the tooth enamel. These results suggest that the tooth inlay were made for therapeutic purposes, using healthy tooth grains as inlay materials which were glued into the prepared teeth to fill it up.

Ion beam analysis of copper selenide thin films prepared by chemical bath deposition

Abstract Analyses of Rutherford back scattered (RBS) 4 He + -particle spectra of copper selenide thin films deposited on glass slides by chemical bath were carried out to determine the changes brought about in the thin film by annealing processes. The atomic density per unit area and composition of the films were obtained from these measurements. This analysis shows that annealing in a nitrogen atmosphere at 400°C leads to the conversion of CuxSe thin film to Cu2Se. Results of X-ray diffraction, optical, and electrical characteristics on the films are presented to supplement the RBS results.

Characterization of high nitrogen content carbon nitride thin films by RBS and infrared techniques

Abstract Carbon nitride compounds have attracted much interest due to the predicted superior properties of C 3 N 4 . Carbon nitride thin films have been produced by reactive DC magnetron sputtering and rf PECVD. Of paramount importance to study the growth of CN films is the accurate determination of their composition in order to evaluate whether an ideal phase can be obtained. The film composition and density were obtained using 1.94 MeV 4 He + RBS. The films have been also characterized by FTIR spectroscopy, profilometry and ellipsometry.

ANALYSIS OF MEXICAN OBSIDIANS BY IBA TECHNIQUES

Abstract Motivated by archaeological interest, an interdisciplinary work is presented, which consists of the characterization of obsidian samples from different mineral sites in Mexico, undertaken by Ion Beam Analysis techniques to assess elemental compositions. The oxygen concentration is obtained by means of the 16O(d,p)17O reaction, and other elements, ranging from K to Br, were analyzed by PIXE using an external beam facility. The determination of the Na, Al and Si content were carried out by PIGE analysis, RBS analysis (using alpha particles) was employed to determine the O, Si and Fe concentrations.

Ion beam analysis of SiCx thin films using a deuterium beam

Abstract SiC x thin films have been prepared using RF reactive magnetron sputtering. The deposition parameters were varied over a wide range to optimise the quality of the films. The film atomic density per unit area (atoms/cm 2 ) and composition were obtained by NRA and RBS techniques by bombarding the samples with a low energy deuterium beam. The films were also characterised by X-ray diffraction, FTIR spectroscopy, profilometry and ellipsometry to supplement the RBS and NRA results.

RBS and NRA of cobalt oxide thin films prepared by the sol-gel process

This work presents a study of cobalt oxide thin films produced by the sol-gel process on aluminum and glass substrates. These films have been analyzed using two ion beam analysis (IBA) techniques: a) a standard RBS 4He 2 MeV and b) nuclear reaction analysis (NRA) using a 1 MeV deuterium beam. The 12C(d,p0)13C nuclear reaction provides information that carbon is incorporated into the film structure, which could be associated to the sinterization film process. Other film measurements such as optical properties, XRD, and SEM were performed in order to complement the IBA analysis. The results show that cobalt oxide film coatings prepared by this technique have good optical properties as solar absorbers and potential uses in solar energy applications.

Analysis of coated reflective glasses near the surface using IBA techniques

Abstract Commerical coated reflective float glasses with different colors were analyzed near the surface using IBA techniques. The coatings are produced on a large glass plate surface (typically about 2.7 m × 5.5 m) by the ion plasma technique using magnetron sputtering deposition of titanium nitride and stainless steel. Conventional 1.850 MeV alpha particle and 2 MeV proton PIXE analyses were used to measure the film thickness and the stoichiometry of the glass coated films. The RBS technique was also used to analyze the glasses on the uncoated side, and tin diffusion near the surface was observed.