Depuis plusieurs années dans les laboratoires UTINAM et FEMTO-ST, des études sont réalisées sur les propriétés tribologiques des monocouches auto-assemblées (SAMs). Ces travaux ont permis la création de la start-up AFUludine SAS en septembre 2016 proposant l’utilisation d’acides phosphoniques comme lubrifiant pour l’emboutissage de tôle d’acier inoxydable. En conséquence, il a fallu développer de nouvelles méthodes permettant l’élaboration de ces films organiques. Les substrats ainsi traités ont montré, en plus de la formation d’une monocouche sur la surface, l’apparition d’agrégats d’acides phosphoniques visibles à l’œil nu.Cette thèse a pour objectif de chercher à mieux comprendre le greffage et les propriétés tribologiques de ces revêtements, ainsi que d’anticiper et de répondre à certaines problématiques industrielles. Les effets des ultrasons haute fréquence (575 kHz) sur le greffage des SAMs sont observés, en s’intéressant dans un premier temps, à un modèle (thiols/or) puis au système d’intérêt. Les US activent le greffage des thiols sur or en diminuant le temps nécessaire pour obtenir un film compact et bien organisé. Les mêmes résultats sont constatés pour les acides phosphoniques sur acier inoxydable.Une seconde partie de ce travail est consacrée à l’étude des agrégats. Leur formation est divisée en plusieurs étapes qui dépendent de la concentration en molécules actives au sein de la solution de modification. Le caractère viscoélastique des agrégats indique une dépendance à cette concentration. L’un des risques industriels du greffage de ces films réside dans la nécessité d’utiliser un solvant organique, comme l’éthanol. Le remplacement de ce solvant par de l’eau pour la modification par des acides phosphoniques de petites chaines alcanes sera donc étudié. La désorption des molécules est également investiguée. En effet, une fois l’emboutissage réalisé, les finitions de la pièce demandent un état de surface spécifique. Pour se faire, l’utilisation d’ultrasons basse fréquence, de soude ou la combinaison des deux, est mise à profit, afin de nettoyer les tôles d’acier à divers degrés : élimination des agrégats redonnant l’aspect visuel d’origine à l’acier inoxydable, désorption des espèces présentes dans le film organisé (agrégats, multicouches et espèces physisorbées) et désorption complète des molécules. / For several years, UTINAM and FEMTO-ST laboratories studied tribological properties of self-assembled monolayers (SAMs). These works enabled the creation of the start up AFULudine SAS on September 2016 offering the use of phosphonic acids as lubricants for stainless steel sheets stamping. Consequently, new methods for the elaboration of such organic films had to be developed. The treated substrates showed formation of phosphoric acid aggregates on the surface, along with the grafting of a monolayer.This thesis aims to better understand the grafting and the tribological properties of these films, as well as to anticipate and answer some industrial issues. The effects of high frequency ultrasound (575 kHz) on the grafting of the films were observed. First, a reference system (thiols/gold) was studied before getting started with the system of interest. Ultrasound activates the grafting of thiols on gold by diminishing the necessary time for obtaining a compact and organized film. Same results were observed for phosphonic acids on stainless steel.The second part of this work is dedicated to the study of aggregates. Their formation is divided into several steps depending on the concentration of active molecules within the modification solution. Viscoelastic properties of the aggregates indicate a dependence to this concentration. The use of an organic solvent, such as ethanol, is one of the industrial drawbacks. The replacement of this solvent with water for the grafting of short chains phosphonic acids is studied. Desorption of these molecules is investigated as well. Indeed, after stamping, specific surface state is required for piece finishing. In order to do so, use of low frequency ultrasound, caustic soda or use of both is carried out to clean steel sheets at several levels: removal of the aggregates giving back the original visual aspect, desorption of the species present in the organic film (aggregates, multilayers and physisorbed species) and complete removal of the molecules.

[pt] Neste trabalho estudamos a síntese e caracterização de nanotubos de carbono de parede simples dopados com boro, que foram produzidos em diferentes condições, usando um precursor líquido em um sistema CVD de alto vácuo. Para a caracterização comparamos as amostras com outras − de referência sem dopagem − e também usamos microscópios de transmissão e varredura, espectroscopia Raman e espectroscopia por fotoelétrons excitados por raio X (XPS). A microscopia de transmissão e a espectroscopia Raman foram usadas para confirmar a presença de nanotubos de parede simples, enquanto a microscopia de varredura foi usada para identificar em qual faixa de temperatura os nanotubos foram produzidos. Achamos evidências de que as amostras estão dopadas ao compararmos os espectros Raman dos nanotubos com as amostras de referência. Usando os resultados do XPS, determinamos que os nossos tubos estão dopados com boro. Comparando a análise Raman com esses resultados, desenvolvemos uma regra simples para estimar o nível de dopagem a partir de medidas Raman. / [en] We studied in this work the synthesis and characterization of boron doped single wall carbon nanotubes. They were produced, at different conditions, using a new liquid precursor in a high vacuum chemical vapour deposition system. In order to characterize the samples we compared them to an undoped reference sample and used a transmission and field emission scanning electron microscopy, Raman spectroscopy and a X-ray photoemission spectroscopy (XPS). The transmission electron microscopy and the Raman spectroscopy were used to confirm the presence of single wall carbon nanotubes, while the scanning electron microscopy was used to identify in which temperature range the tubes were produced. We found evidences that the produced sample were doped by comparing the Raman spectra of the samples with the reference one. By using the XPS, we could determine that our tubes are boron doped. By comparing the Raman analysis with the XPS results, we developed a simple rule to estimate the doping level through Raman measurements.

Neste trabalho foi estudado o desenvolvimento de uma superfície modelo de silício monocristalino, SiO2/Si, modificada com organossilanos derivados de N-heterocíclicos que permitisse a imobilização de um complexo de coordenação, FeTIM. Estas superfícies modificadas poderão ser empregadas em estudos de reatividade frente a analitos de interesse, como o NO. Sob esse aspecto, a síntese desses novos silanos, contendo N-heterocíclicos, e o desenvolvimento de uma metodologia de formação dos filmes finos automontados, sobre a superfície de SiO2/Si, tornou-se de grande relevância na aplicabilidade deste trabalho. Para a obtenção dessas superfícies, fez-se necessária a compreensão dos parâmetros de formação dos filmes de silanos. Os parâmetros estudados foram os efeitos do tempo de adsorção, da concentração da solução dos silanos, da polaridade do solvente e do tamanho da cadeia alquílica do silano no processo de formação dos filmes. Deste modo, foi possível inferir sobre as alterações na morfologia e na estrutura química dos filmes formados, através de medidas de Espectroscopia de Fotoelétrons excitados por Raios-X (XPS), Microscopia de Força Atômica (AFM) e Microscopia Eletrônica de Varredura (MEV). A imobilização do complexo de FeTIM sobre a superfície organomodificada foi comprovada pela variação da linha de fotoemissão do Fe 2p nas medidas de XPS. / This work describes the study of model surfaces on oxidized silicon wafer, SiO2/Si, modified with N-heterocycles rings, that allows the grafting of a macrocycle iron complex, FeTIM, that could be used in reactivity studies, with biologically relevant molecules, as nitrogen monoxide (NO). On this way, the synthesis of these silanes and a new methodology of the formation of self-assembled monolayers had become a relevant question on this work applicability. These thin films contain silanes bearing nitrogenated Lewis bases on silicon surfaces. In order to obtain these modified surfaces, it was necessary a comprehensive study of the adsorption parameters of the thin films. The parameters studied were the effect of: adsorption time, the solution concentration, the role of the solvents polarity and the chain length alkylsilanes in the film formation. Then, it was possible to infer about the film\'s morphology differences and chemical structures by the XPS, AFM and MEV measurements. X-ray photoemission lines of Fe 2p were used to probe the iron chemical environment in the chemically adsorbed macrocycles complexes.

Nesta dissertação estudou-se a influência dos parâmetros de pós-tratamento eletroquímico, em condições potenciodinâmicas, sobre a estabilidade e reatividade frente à organofosfatos do filme eletrodepositado de hexacianoferrato (II) de ferro (III), mais conhecido como azul da Prússia (PB). O pós-tratamento do filme em baixas velocidades de varredura leva à formação do PB \"solúvel\" com a formação de grãos maiores e um filme mais estável eletroquimicamente como demonstrado por ensaios de voltametria cíclica (VC), microscopia de força atômica (AFM) e espectroscopia de fotoelétrons excitados por raios X (XPS). Filmes pós-tratados em meio HCl/KCl 0,1M foram mais eletroquimicamente estáveis em meio ácido, enquanto filmes submetidos à pós-tratamento em meio neutro foram mais estáveis em meio neutro. / In this work it was studied the influence of the electrochemical posttreatment parameters in potenciodinamics conditions on the stability and reactivity against organophosphates by eletrodepositaded iron (III) hexacyanoferrate (II), better known as blue of Prussia (PB). The posttreatment of the film at low sweep rates leads to the formation of the PB \"soluble\" with the formation of larger grains and a more electrochemically stable films as demonstrated by cyclic voltammetry (VC), atomic force microscope (AFM) and X-ray photoelectron espectroscopic (XPS) tests. Films post-treated in HCl/KCl 0.1 M media were more electrochemically stable in an acid media, while films submitted to post-treatment in neutral media were more stable in neutral media.

Submitted by Biblioteca do Instituto de Física (bif@ndc.uff.br) on 2017-03-27T19:05:26Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Tese _ficha cartalografica.pdf: 12047542 bytes, checksum: 15c5c46a6007c1cf0e93d34e697f4e96 (MD5) / Made available in DSpace on 2017-03-27T19:05:26Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Tese _ficha cartalografica.pdf: 12047542 bytes, checksum: 15c5c46a6007c1cf0e93d34e697f4e96 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Neste trabalho estudamos o comportamento ferromagnético de uma série de multicamadas de ZnO/MT com MT = Fe, CoFe, NiFe. Este tipo de sistemas é importante por suas aplicações na spintrônica; cálculos teóricos em multicamadas de ZnO/Co fixando a espessura da camada do ZnO em 5 nm, mostram que estas estruturas podem ter até 100% de polarização de spin. As multicamadas com estrutura [ZnO(5nm)/MT(t)]x6 foram crescidas por magnetron sputtering variando a espessura do MT numa série de valores t = 0,3; 0,4; 0,6; 0,8 e 1,0 nm. A estrutura cristalográfica foi analisada com um difratômetro de raios-X (DRX), revelando um crescimento preferencial no plano (002) do ZnO e mostrando um alargamento de linha e picos satélites. A topografia foi analisada com um microscópio de força atômica (AFM), e revela uma relação entre a espessura do MT com as imperfeições da superfície. A resposta magnética estática foi analisada com um magnetômetro de amostra vibrante (VSM) obtendo curvas de magnetização em função do campo (M vs. H) e curvas de magnetização em função da temperatura (M vs. T) pelo método de medidas de zero field cooling (ZFC) e field cooling (FC). As formas das curvas de histerese revelam a mudança da serie, de um filme com interação dipolar forte a um sistema de nanopartículas não interagentes dependendo da “concentração” do MT na multicamada; as medidas de ZFC/FC confirmam que a ordem ferromagnética é favorecida quanto maior é a espessura depositada do MT. A resposta magnética dinâmica foi analisada por espectroscopia de ressonância ferromagnética (FMR), e revela o decrescimento do campo de ressonância na serie, devido á anisotropia de forma, mostrando uma mudança do eixo fácil da magnetização do plano para a perpendicular. Análise química foi feita por espectroscopia de fotoemisão de raios-X, e revela a formação de fases mistas (íons) coexistindo com o MT; e por último medidas de transmitância revelam a existência de um pico plasmon na faixa de 250 – 340 nm. Estes picos de plasmon são característicos de sistemas dielétricos com nanopartículas. O tratamento térmico de 6000C por 2 horas em vácuo da multicamada [ZnO(5nm)/Fe(t)]x6 teve a finalidade de incrementar a espessura do semicondutor magnético diluído (SMDs) na multicamada, mediante a difusão do MT na rede do ZnO; estes sistemas revelam uma mudança nas suas propriedades estruturais e magnéticas e possivelmente o aparecimento do SMDs, devido a que seu comportamento magnético não corresponde a de um filme nem a de um sistema granular. / In this work we study the ferromagnetic behavior of a series of multilayer ZnO / MT with MT = Fe, CoFe, NiFe. Such systems are important for applications in spintronics: theoretical calculations in multilayer of ZnO/Co with fixed ZnO thickness of 5 nm show that these structures can have up to 100% spin polarization. The multilayers with structure of [ZnO (5nm) / MT (t)] x6 were grown by means of magnetron sputtering varying the thickness of the MT with the values of t = 0,3; 0,4; 0,6; 0,8 and 1, 0 nm. The crystallographic structure is analyzed by X-ray diffractometer (XRD) and the results revealed a preferential growth of ZnO along (002) plane, enlargement of the width of the peaks and existence of satellite peaks. The topography is analyzed with the atomic force microscope (AFM) and it reveals a relationship between the thicknesses of the MT layers and the surface imperfections. The static magnetic response was analyzed with a vibrating sample magnetometer (VSM) and magnetization curves as a function of field (M vs. H) and as a function of temperature (Mvs. T) using the zero field cooling measurements (ZFC) and field cooling (FC) were obtained. The shapes of hysteresis curves show the changes of a film with strong dipolar interactions to a system of non-interacting nanoparticles according to the "concentration" of MT in the multilayer. Measurements of ZFC / FC M-T curves confirm that the ferromagnetic order is favored in the samples with thicker deposited MT layers. The dynamic magnetic response was analyzed by ferromagnetic resonance spectroscopy (FMR) and it shows the decrease of the resonance field in the series, which is due to the shape anisotropy, showing a change of the easy axis of magnetization from in plane to the perpendicular of the plane. The chemical analysis is done by X-ray photoemission spectroscopy (XPS) and the result shows the formation of mixed phases (ions) of the MT. Transmittance measurements reveal the existence of a peak of plasmon in the range of 250 to 340 nm. These peaks of plasmon are characteristic dielectric systems with nanoparticles. Heat treatment for the sample of [ZnO (5nm) / Fe (t)] x6 has been done at 600oC for 2 hours in vacuum in order to increase the thickness of diluted magnetic semiconductor (SMDs) layers in the multilayer system due to the diffusion process of MT atoms. These systems show changes in their structural and magnetic properties, which can be due to the appearance of SMDs since the magnetic behavior does not match to a film or to a granular system.

Ce travail porte sur le développement de protocoles de croissance par CVD à injection directe de liquide (DLI-CVD) de films catalytiques poreux potentiellement utilisables dans les piles à combustible de type PEMFC. Les objectifs étaient de contrôler et de réduire au maximum la charge en platine, d’obtenir des matériaux à grande surface spécifique, c'est-à-dire très poreux, mais aussi d’utiliser des précurseurs à bas coût.Dans un premier temps, le platine a été promu par de l’oxyde de cérium, matériau qui possède lui-même des propriétés catalytiques. L’optimisation des paramètres de croissance a montré le rôle majeur de la température de dépôt mais aussi du flux des précurseurs sur la morphologie finale des films. Un dopage contrôlé en platine de la surface de l’oxyde de cérium a ainsi pu être mis au point à partir du dépôt simultané de cérine et de platine. Le flux de précurseur du platine a alors permis d’ajuster la charge et l’état d’oxydation de cet élément au sein des films sans pour autant modifier leur porosité. Il est, par exemple, possible d’élaborer des films minces d’oxyde de cérium composés de particules nanométriques dopées en extrême surface avec 5 % de platine à l’état +II. L’effet du flux de précurseur sur l’état d’oxydation du platine a été confirmé pour le système Pt/TiO2. Dans un second temps, des oxycarbures de tungstène ont été synthétisés de façon à éliminer totalement le platine du catalyseur. Un procédé en deux étapes a été mis au point permettant d’obtenir des dépôts d’oxycarbure de tungstène possédant de grandes surfaces spécifiques en déposant un film utra-mince et conforme d’oxycarbure sur une couche poreuse d’oxyde de tungstène. / This work is focused on development of growth protocols by direct liquid injection chemical vapor deposition (DLI-CVD) of catalytic porous films which could be used in proton exchange membrane fuel cells (PEMFC). The aim of this work was to reduce or even proscribe platinum in catalysts having large specific surface area i.e. being very porous. Besides, the aim is also to use mainly low cost precursors.Cerium oxide, which is a material widely used as catalyst, has been chosen to partially substitute platinum. Porous CeO2 layers were obtained by the optimization of processing parameters such as deposition temperature or precursors flow rates. Controlled platinum doping of cerium oxide surface has been obtained from deposition of ceria and platinum at the same time. The platinum precursor flow rate has allowed adjusting the load and the oxidation state of Pt in films without changing their porosity. For example, it was possible to synthesize thin cerium oxide films composed of surface Pt doped nanoparticles. In such a case, the Pt content is 5% in top most layers and its oxidation state is +II. The effect of precursor flow rate on the platinum oxidation state was confirmed from the study of the Pt / TiO2 system. Finally, platinum has been fully replaced by tungsten oxycarbide. A two steps process has been developed to obtain porous oxycarbide layers by depositing a conformed tungsten oxycarbide ultra-thin film on a porous tungsten oxide layer.

La miniaturisation des appareils électroniques et la multiplication de leur fonctionnalités explique l’intérêt croissant porté aux microsources d’énergie telles que les microbatteries au lithium. Ces dernières sont principalement conçues pour une utilisation rechargeable, mais des systèmes non rechargeables peuvent également êtes envisagés pour certaines applications. Actuellement, la principale limitation de ces systèmes est leur capacité surfacique, n’excédant pas 200 µAh.cm-2. Afin d’obtenir une forte capacité surfacique, nous nous sommes intéressés à CuO, un matériau réagissant avec le lithium suivant un mécanisme de conversion, et présentant une capacité volumique théorique élevée (425 µAh .cm-2.µm-1). Des couches minces de CuO ont ainsi été préparées par pulvérisation radiofréquence à cathode magnétron sous atmosphère réactive (Ar + O2). L’influence des paramètres de dépôts (concentration d’oxygène, pression totale, température des substrats, distance cible-substrat, configuration de la cible) sur leurs propriétés chimiques, morphologiques et structurales a été étudiée. Ces dernières ont également été corrélées à leurs performances électrochimiques, obtenues avec un électrolyte liquide ou un électrolyte solide. / The miniaturization of electronic components and their increasing number of functionalities induce a great interest for energy microsources such as thin films batteries. There are mainly developed for secondary systems, even if primary systems are also convenient for some applications. Currently, the main limitation is their specific capacity which does not exceed 200 µAh.cm 2.µm 1. In order to get a system having a high surfacic capacity, we focused on CuO, which react with lithium according to a conversion mechanism and exhibit a large theoretical capacity (425 µAh .cm-2.µm-1). CuO thin films were prepared by radiofrequency magnetron sputtering in a reactive mixture (Ar + O2). The influence of some deposition parameters (oxygen concentration, total pressure, substrate-target distance, the intentional heating or not of the substrates, target configuration) on their chemical, morphological and structural properties were investigated. The latter were also linked to their electrochemical performances, obtained with a liquid electrolyte or a solid electrolyte.

Water aerosols affect the climate because they have an impact on the radiation balance and cloud formation. Water is present in all forms in the atmosphere (water, ice and steam), for example as rain and hail. Water aerosols play an important role in many biological and chemical processes in the atmosphere. The most common form of water in the atmosphere is water droplets or vapor which often come from oceans and lakes and these aerosols often contain organic compounds. It is therefore interesting to study if organic compounds, in this case glycerol, will reside on the surface or inside the water droplets. The investigations were performed by using theoretical studies, molecular dynamic simulations in GROMACS, and experimental investigations; X-ray photoelectron spectroscopy with a liquid jet. The experiments were performed at BESSY II, Berlin. The concentrations of glycerol were varied from 75:1; 8:1 to 4:1 (water: glycerol molecules). The results were that the experiments and simulations indicated that when theconcentration of glycerol increased the glycerol concentration at the surface of the waterdroplet increases until a monolayer of glycerol molecules was formed at the surface. When the monolayer was formed (or close to) less and less glycerol molecules were placed at thewater surface and more and more glycerol molecules were placed in the bulk of the waterdroplet. / Vattenaerosoler påverkar klimatet eftersom de har en inverkan på strålningsbalansen och molnbildningen. Vatten finns i alla former i atmosfären (vatten, is och ånga) som bland annat regn och hagel. Vatten aerosolerna spelar en viktig roll i många kemiska och biologiska processer i atmosfären. Den vanligaste formen av vatten i atmosfären är små vattendroppar eller ånga som ofta kommer från hav och sjöar och som ofta innehar organiska föreningar. Då vattenaerosoler påverkar klimatet och organiska föreningar är vanligt förekommande i vattendroppar är det intressant att undersöka om organiska föreningar, i detta fall glycerol, hamnar på ytan eller inuti vattnet. Undersökningarna har gjorts genom att använda teoretiska perspektiv, molekylärdynamiska simuleringar i GROMACS, samt experimentella undersökningar i form av röntgen fotoelektronspektroskopi med en vätskejet. Dessa experiment utfördes i BESSY II, Berlin. Koncentrationerna av glycerol varierades från75:1; 8:1 till 4:1 (vatten: glycerolmolekyler). Resultaten från experimenten och simuleringarna indikerade att när koncentrationen av glycerol ökade så ökade glycerolkoncentrationen på ytan av vattendroppen tills det bildades ett monolager av glycerolmolekyler på vattenytan. När monolagret hade bildats så placerades mindre och mindre glycerolmolekyler på vattenytan och fler och fler glycerolmolekyler placerades inne i vattendroppen.

L'objectif de cette thèse est d'étudier les propriétés physico-chimiques des surfaces et des interfaces des couches minces par spectroscopie de photoémission (XPS), diffraction des photoélectrons (XPD), et la photoémission résolue en temps (PTR). Les expériences sont réalisées en utilisant une source standard des rayons X AlKa à l'INL ou les rayons X mous auprès du synchrotron Soleil. La première étude sur le système Pt/ Gd203/ Si(111) a montré que le transfert de charge entre le Pt et 0 à l'interface Pt/Gd203 implique un déplacement chimique de niveau Pt4f sans modification des caractéristiques de la composante métallique des spectres XPS. L'étude XPD montre que Pt se cristallise partiellement en deux domaines : [110] Pt(111) // [110] Gd203 (111) et [101] Pt(111) / / [110] Gd203 (111). De plus, une autre phase ordonnée d'oxyde de platine Pt02 à l'interface a été observée. A travers la caractérisation de la morphologie déterminée par la technique AFM et XPD, nous avons discuté l'adhésion aux interfaces métal/oxyde. La deuxième étude traite l'évolution d'interface d'un système modèle : métal non réactive/ semi-conducteur, dépendent fortement des conditions thermodynamiques. Nous avons étudié la couche mince d'Au déposée sur le substrat Si(001) par photoémission résolue en temps (TEMPO- synchrotron Soleil). L'étude XPS, montre avant le recuit la formation de l'oxyde native Si02 sur l'heterostructure à température ambiante. La désorption de cet oxyde se produit à faible température et induit une décroissance de l'intensité des photoélectrons durant le temps de recuit. La désorption de l'oxyde Si02 et la formation de l'alliage AuSi sont responsables de la gravure et la formation des puits de forme cubique à la surface de Si due à l'activité catalytique de l'Au. La troisième étude concerne la croissance du graphène à partir de cristal de SiC(0001)- face Si par décomposition thermique. Le niveau de coeur C1s résolu en trois composantes principales sont associées au carbone de 6H-SiC, de graphène, et l'interface graphène/ 6H-SiC (0001). L'intensité de chaque composante est rapportée en fonction de l'angle polaire (azimutale) pour différents angles azimutales (polaire). Les mesures XPD fournissent des informations cristallographiques qui indiquent clairement que les feuillets de graphène sont organisés en structure graphite sur le substrat 6H-SiC (0001). Cette organisation résulte de l’effondrement de la maille de substrat. Enfin, le découplage à l'interface graphène/ 6H-SiC (0001) par l'oxygène a été étudié par XPS. La dernière étude concerne la croissance du film mince d'InP par MBE sur le substrat SrTi03 (001). L'intégration des semi-conducteurs III-V sur le Si, en utilisant la couche tampon d'oxyde SrTi03 est l'objet des intenses recherches, en raison des applications prometteuses dans le domaine de nano-optoélectronique. Les niveaux de coeur O1s, Sr3d, Ti2p, In3d, P2p ont été analysés et rapportés en fonction de l'angle azimutale à différents angles polaires. La comparaison des courbes XPD azimutales de Sr3d et In3d montre que les ilots InP sont orientées (001) avec la relation d'épitaxie; [110]InP(001 )/ / [100]! SrTi03 (001). La caractérisation morphologique par AFM montre des ilots InP facettés régulièrement dispersée à la surface. / The main objective of this thesis is to study the chemical and physical properties at the surface or at the interface between thin layers by photoemission spectroscopy (XPS), photoelectron diffraction (XPD), and time resolved photoemission (PTR) . The experiments were conducted using an Alka source at INL or soft -X ray synchrotron radiation at Soleil, the French national Synchrotron facility. The first photoemission study has been performed on platinum deposited on thin Gd2(h layers grown by Molecular Bearn Epitaxy (MBE) on Si (111) substrate. The charge transfer between Pt and 0 at the interface causes a chemical shift to higher binding energies without changing the characteristic shape of the metal XPS peak. The XPD study shows that Pt is partially crystallized into two (111)-oriented do mains on Gd20 3 (111) with the in-plane epitaxial relationships [11 0] Pt (111) / / [11 0] Gd203 (111) and [101] Pt(111)/ / [11 0] Gd20 3 (111). In addition to bi-domains formation of platinum Pt (111) on Gd20 3 (111), a new ordered phase of platinum oxide Pt02 at the Pt/ Gd203 interface have been observed. The study of the background of the polar curves depending of the morphology has shown, that the film of Pt does not wet on the oxide, due to the low energy of interaction at the interface compared to the Pt thin layer. The second study has been interested to the photoemission time-resolved study of non-reactive metal / semiconductor model system. We have studied the thin layer gold (Au) growth on silicon (Si) substrate before and during annealing in TEMPO beam line (synchrotron Soleil).The XPS study, shows before annealing the formation of silicon native oxide on heterostructure at ambient temperature. The desorption of silicon oxide during annealing at low temperature induce photoemission intensity decreases with time. The desorption of oxide and alloy formation (AuSi) induce distribution of pits with cubic form at silicon surface due to gold etching activity. The third photoemission study has concerned thin films of a few layers of graphene obtained by solid-state graphitization from 6H-SiC (0001) substrates have been studied by X-ray photoelectron spectroscopy (XPS) and X-ray photoelectron diffraction (XPD). The Cls core-level has been resolved into components, which have been associated with carbon from bulk SiC, carbon from graphene and carbon at the interface graphene/ 6H-SiC (0001). Then, the intensity of each of these components has been recorded as a function of polar (azimuth) angle for several azimuth (polar) angles. These XPD measurements provide crystallographic information which clearly indicates that the graphene sheets are organized in graphite-like structure on 6H-SiC(0001), an organization that results of the shrinking of the 6H-SiC (0001) lattice after Si depletion. Finally the decoupling of graphene from 6H-SiC (0001) substrate by oxygen intercalation has been studied from the XPS point of view. Finally, photoemission study has concerned thin film of InP (phosphor indium ) islands grown by Molecular Bearn Epitaxy (MBE) on SrTi03 (001) bulk substrate have been investigated by X-ray photoelectron spectroscopy and diffraction (XPS/ XPD).Integration of III-V semi-conductor on silicon wafer, via SrTi03 buffer is currently the subject of intense research because of its potentially interesting applications in future nano-optoelectronics. The Ols, Sr3d, Ti2p, In3d, and P 2p core level area have been studied as function of azimuth angle for different polar angles. Comparison of the XPD azimuth curves of Sr3d and In3d shows that islands InP are oriented (001) with an in-plane epitaxial relationship [110] InP(001 ) // [100] SrTi03 (001). AFM images shows that InP islands are regularly dispersed on the surface. Their shape is a regularly facetted half-sphere.

Au point de convergence entre les sciences fondamentales et les sciences appliquées, les nanosystèmes connaissent depuis une dizaine d'années un développement industriel à l'échelle planétaire. Parmi ces nanosystèmes, les agrégats, petites particules constituées de quelques atomes (ou molécules) à plusieurs milliers d'unités, constituent véritablement "le chaînon manquant" entre l'atome isolé et le solide massif. L'étude des interactions dans les agrégats permettrait de comprendre comment l'atome est influencé par son environnement lorsqu'il est inclus dans un système dense au sein d'autres atomes. La nanoparticule (NP) est constituée de plusieurs milliers à millions d'atomes, ses dimensions étant exprimées en nanomètres (nm, 1 nm = 10^{-9} m).L'engouement que suscitent les agrégats et les NPs est lié à leurs propriétés physiques particulières mais également à leur grande surface spécifique (rapport surface/volume). Il en résulte une grande réactivité liée à des sites réactionnels plus nombreux. Cette caractéristique est exploitée dans de très nombreux domaines d'applications (catalyse hétérogène, dépollution, photovoltaïque, nanomédecine).Cette expansion des activités "nanotechnologiques" implique le développement de méthodes de caractérisation de ces nouveaux types de matériaux, qui sont bel et bien présents dans notre vie.Parmi les méthodes de caractérisation de la matière, la spectroscopie de photoélectrons (XPS) générés par rayonnement synchrotron a, depuis longtemps, prouvé son efficacité pour l'étude des atomes, molécules et des matériaux, et s'est imposée en tant que technique de choix en science des surfaces. L'idée de ces travaux de thèse est de combiner la sélectivité atomique de la spectroscopie appliquée à la matière diluée, avec la sensibilité de surface de la spectroscopie X-mous sur les matériaux pour étudier des nanosystèmes (agrégats et NPs) en phase gazeuse par XPS dans le domaine d'énergie allant de 100 eV à 1000 eV.Nous présentons dans cette thèse les premiers résultats obtenus par cette approche sur la ligne de lumière PLEIADES du synchrotron SOLEIL, ligne à ultra-haute résolution dédiée à l'étude de la matière diluée. Les expériences ont porté sur des matériaux très utilisés dans les secteurs industriel et biomédical, en l'occurrence les NPs de TiO2, de Silicium et les NPs de polystyrène fonctionnalisées par des dérivés glucidiques}. Nous montrons comment l'XPS de NPs isolées nous permet de répondre à des questionnements concrets, comme la réactivité de surface des NPs, les processus et les dynamiques d'oxydation, l'inclusion d'hétéroatomes ainsi que l'interface ligand/NP. Les résultats présentés ici montrent non seulement la faisabilité de la méthode, mais plus encore, prouvent qu'il est possible d'adresser des problématiques appliquées ayant trait à des phénomènes réactionnels surfaciques, sur des NPs isolées, aléatoirement orientées. / During the past decade, a world-wide industrial expansion of nanosystems has been taking place at the junction between fundamental and applied sciences. Among these nanosystems, clusters, defined as small particles whose constitution ranges from few atoms (or molecules) to several thousand units, constitute "the missing link" between the isolated atom and the bulk solid. Studying the interactions in the aggregates would allow to understand how the atom is influenced by its neighborhood when it is included in a dense system within other atoms. "Nanoparticle" (NP) is usually defined as a system extanding from several thousands to millions of atoms, and its size is expressed in nanometer (nm, 1 nm = 10^{-9} m).This interest for nanosystems mainly results from their particular physical properties at the nanometer scale, but also from their large "surface to bulk" ratio. Hence, more active sites are available at the surface, enhancing their reactivity. This characteristic is used in numerous fields of applications (heterogeneous catalysis, cleanup, photovoltaics, nanomedicine).% and is also relevant in natural processes (atmospheric sprays, volcanic eruptions).This expansion of the "nanotechnological" activities involves the development of new methods for the characterization of these new kinds of materials, which take a considerable part in our daily life. Among the methods of matter characterization, synchrotron radiation based soft X-ray spectroscopy has shown to be a powerful technique for the study of atoms and molecules as well as materials, and appears today as an efficient technique of characterization in surface science.The idea of this thesis is to combine the atomic selectivity of the spectroscopy applied to dilute matter, with the surface sensitivity of soft X-ray spectroscopy, to study isolated nanosystems (clusters and NPs) in the gas phase, by XPS in the energy range of soft X-ray (typically 100 eV to 1000 eV). We present in this thesis the first results obtained by this approach at the PLEIADES beamline of SOLEIL synchrotron radiation facility. PLEIADES is a ultra-high resolution beamline dedicated to the study of dilute matter. The experiments carried out in this work relate to materials often used in the industrial and biomedical fields: TiO2 NPs, Silicon and glycosylated polystyrene NPs. We show how XPS on isolated NPs allows us to answer concrete questions, as the surface reactivity of the NPs, processes and oxidation dynamics, the doping efficiency or the interface ligand/NP. The results presented here not only show the feasibility of the method, but much more than that, prove that it is possible to give insight about surface chemical processes occuring on isolated, randomly oriented NPs.