STUDY MATERIAL OF TECHNOLOGICAL ANALYSIS TECHNIQUES THROUGH ION BEAMSAuthor:
MORILLA GARCÍA YOLANDA.
Year:
2005.
University:
SEVILLA [
www.us.es].
Place of defense: CENTRO NACIONAL DE ACELERADORES.
Place of preparation: CENTRO NACIONAL DE ACELERADORES.
Summary: The use and potential of nuclear techniques based on ion beams within the materials science are little known and our country. The development of new methodologies to address issues that had not been solved so far shows the role they can play these techniques within the framework of the current materials research, including the degree of complementarity with other techniques. In the first chapter we review the techniques used to accomplish this thesis with special attention to reetrodispersión elastic particles (RBS), the use of resonance and ion channeling, as well as an analysis by nuclear reactions Detection particles (NRA) and gamma radiation (PIGE). Over three chapters present the extensive studies of three different systems that for one reason or another are interesting from a technological point of view. The properties of this material particularly dependent on their oxygen content. There have been overall oxygen content using the reaction 16O (3He,) 150 and the membership has been established by RBS with cationic alpha particles to 3,045 MeV, using resonance elastic 16O (a) 16O to determine the distribution of oxygen. Under certain conditions of deposition shown an excess of oxygen corresponding to 8 atoms of oxygen by celada, unit. The analysis, by absorption spectroscopy Rays near the edge absorption (Xanes) CU-L indicate that the excess oxygen does not belong to parasitic stages of other compounds, and also show the emergence of a sharp peak, himself doping in a hollow 3D9L by the oxígenos content at the CUO2 in superconducting compounds based on copper. A proper combination of RBS, NRA and PIGE has allowed us to determine the composition of sheets of a material piezoelectric aluminum nitride (ALN), obtained by spraying cathodic on different substrates, and all this without changing the nature of the material. For the first time were correlated with their physical properties composition. The determination of both the major elements as delineated in quantities of argon and oxygen impurities contained in the samples, has served to establish the most suitable conditions under which achieved growth of ALN layers with a good quality crystalline and oriented in the direction the C axis, which is a prerequisite to be used in electronics devices. We addressed the creation of structural disorder in the semiconductor substrate of silicon carbide (SiC) during ion implantation, depending on the conditions of irradiation, as well as recovery after heat treatment. We have developed a methodology for the study of structural disorder based on the use of resonance 12C (a) 12C A 4.26MeV in geometry pipeline, which combined with a sweeping energy, it produces distributions disorder in the sub - C to low doses. When the structural damage is pronounced, we employ a more routine backscatter alpha particles with energy around 3.5 MEV. So we get both an overview of both sudredes affected following the introduction of the material, and it is possible to assess the damage with the help of a simulation program that allows the analysis of spectra in geometry pipeline. Results highlighted the damage that can be created in the Sic by ion implantation depends as much on the flow of ions and the current density and a crist 8 to fuert 302 emente damaged recovers order to short-range order but lost to long-range.
