Les chondres, témoin des débuts du Système Solaire, ont une origine encore débattue. En particulier, l'origine de leurs olivines est encore mal comprise. Furent-elles formées par processus magmatique ou de condensation ? Héritées ou formées directement dans le chondre ? Pour répondre cette question, une étude chimique détaillée a été réalisée sur des inclusions vitreuses piégées dans les olivines magnésiennes d'Allende (CV3). Des images 3D et des profils chimiques en profondeur des éléments majeurs montrent un comportement chimique similaire à celui d'inclusions magmatiques synthétiques, un argument en faveur d'une origine magmatique. Les inclusions ont ensuite été chauffées à haute température (1 800 °C) grâce à une platine chauffante unique au monde, développée au cours du projet, afin d'étudier le verre homogène. Les teneurs élevées en Na2O des inclusions chauffées montrent que les inclusions évoluent en système fermé et que les olivines se sont formées dans un environnement riche en Na. Du fait de la volatilité du Na à haute température, un tel environnement est difficilement conciliable avec une formation des olivines par condensation ou magmatique au sein des chondres. Ceci suggère donc que les olivines sont héritées. Des mesures de REE ont été réalisées par SIMS dans les inclusions et leurs olivines hôtes afin de calculer le taux de cristallisation nécessaire à la formation de ces olivines. Les compositions chimiques des magmas parents calculés d'après ces taux de cristallisation correspondent à celles attendues d'après les études expérimentales déjà existantes. Celles-ci suggèrent la formation des olivines au sein de planétésimaux fondus de composition CV ou CI / Chondrules, witnesses of the beginning of the Solar System still have a debated origin ti this day. In particular, the origin of chondrules' olivines is still poorly understood. Were they formed by magmatism or condensation processes? Inherited or grown directly within the chondrule? In order to answer this, a detailed chemical study was undertook on glass inclusions trapped in Mg-rich olivines from Allende (CV3) meteorite. 3D images and chemical depth profiles showed a similar behavior between Allende's inclusions and synthetic magmatic ones, which is an argument in favor of a magmatic origin for olivines. Glass inclusions were then heated at high temperature (1 800 °C) via a new and unique heating stage developed during the project, in order to study the homogeneous glasses. High Na2O amounts in heated inclusions show that they behave as closed systems and that olivines formed in a Na-rich environment. Because Na is highly volatile at high temperatures, such an environment is hard to reconcile with olivines forming by condensation or magmatism within chondrules. This suggests that olivines are inherited. Measurements of REE were performed via SIMS in inclusions and hosts olivines in order to calculate the crystallization rates necessary to olivines formation. Chemical compositions of parent magmas, calculated from crystallization rates correspond to those expected from previous experimental studies. They suggest that olivines from chondrules form within molten planetesimals of global CI to CV composition

Understanding volatile evolution associated with active volcanic magmatic systems is of paramount importance because volatiles control and determine the magnitude of an eruption owing to the large change in molar volume that volatile species show depending on their physical state (volatiles dissolved in silicate melts vs. volatiles exsolved as vapor). For active volcanic systems studying the volatile evolution can help to assess the potential hazard associated to a certain locality. Also, volatile evolution in magmatic system controls the formation of certain ore deposits. Despite the importance of understanding volatile evolution of magmatic systems, concentrations of volatiles of evolving magmas are not easily available especially for magmas originated in the deep crust. Fortunately, sample of melts can be entrapped as melt inclusion (MI) into growing igneous minerals in crystalizing magma chamber. After the entrapment, the crystal works as an insulating capsule from the external magmatic environment. Researchers have started to use MI because they provide some advantages in respect to the classical whole rock approach to petrological studies. One of the most important advantages is that MI often represent sample of a deep and non-degassed melt (glass) available at Earth's surface. In fact, with the exception of deep ocean basalts, igneous whole rocks found at the Earth's surface are degassed magmas. This dissertation is a compilation of four publications produced during six years of research and is addressed to give a contribution in understanding the volatile evolution in magmatic systems and also to improve the present understanding of information that can be obtained using the melt inclusions technique. In the first chapter, I present an alternative interpretation of H₂O-CO₂ trends obtained from MI. In this study, we demonstrate that these trends can be due to post entrapment crystallization on the wall of the MI and not to magma ascent. This alternative view is more realistic especially for cases where in the same phenocrysts MI show strongly different CO₂ concentrations. In the second chapter, I present a study to test for the MI reliability in recording volatile concentrations. We used the approach of the melt inclusion assemblage (MIA) that consists of analyzing groups of MI presumably entrapped at the same time and, thus, at same chemical and physical conditions. The results show that most of the MIA studied show consistent volatile concentrations corroborating the reliability of the MI technique. CO₂ shows the highest degrees of variability and we have assessed this behavior mostly to C-contamination in the surface of the sample. The third chapter is a study case (the Solchiaro eruption in Southern Italy) that shows the potential uses of MI to understanding the volatile evolution. I present a model showing the dynamic of the magma based on MI. This study also discusses the origin of anomalous MI and which MI provide the best information. The final chapter is dedicated to test the applicability of the new Linkam TS1400XY heating stage. I was able to show how this new microthermometric tool is capable of homogenizing MI at high temperature and to quench MI to a homogeneous glass state. / Ph. D.

In this thesis we study the interaction of helium, neon, argon and gallium ions with graphene. The graphene structure is contaminated with gallium ions during the graphene processing by focused gallium beam (FIB). The graphene properties are affected, e.g. reducing the electrical conductivity. The aim of this thesis is to verify the effect of selected ion beams on the graphene structure and select suitable ion beam for sputtering. Furthermore, the modification of standard heating stage used in LEIS instrument (Qtac 100) was designed and implemented. The LEIS instrument is connected to the complex UHV system for deposition and analysis of nanostructures – SPECS. This modification allows analysis of selected nanoparticles on suitable substrate at the elevated temperature.