Depuis plus de 45 ans, les colonnes à faisceaux d'ions focalisés FIB à base de source à métal liquide (Ga) sont utilisées pour l'élaboration, la modification ou l'analyse de nanostructures. Beaucoup plus récemment, moins de 10 ans, les sources plasma sont intégrées dans les FIB afin de répondre aux besoins d'analyse de défaillance mais également de préparation d'échantillons. Ce marché des FIB plasma est en forte progression ces derniers années et s'accompagne d'une amélioration permanente des spécifications de cette technologie encore jeune. Il est donc nécessaire de caractériser au mieux ces sources afin de pouvoir améliorer l'optique associée. Dans cette thèse, nous présentons le développement d'une nouvelle colonne FIB fonctionnant avec une source d'ions plasma, dédiée à la création de centres NV, ainsi que le développement d'un outil permettant de caractériser les performances de cette source.Étant donné le contexte de ces travaux, la première partie du manuscrit est consacrée à la présentation de la technologie FIB, de son fonctionnement et de ses applications. Dans le second chapitre, nous présentons le développement d'une colonne FIB dédiée à l'implantation d'ions azote pour la création contrôlée de centres colorés NV dans des diamants. Nous commençons par introduire les propriétés uniques des centres NV ainsi que les méthodes usuelles pour leur création. Nous présentons ensuite les différentes étapes de la caractérisation de cette colonne FIB. Les implantations réalisées au cours de ce travail ont pu être utilisées pour le développement d'une nouvelle application des diamants dopés.Dans le dernier chapitre du manuscrit, nous nous intéressons à la conception d'un banc de test permettant d'obtenir les paramètres clés de la source d'ions, à savoir la dispersion en énergie et l'émittance. Les méthodes usuelles de mesure de ces paramètres sont présentées puis le fonctionnement du banc de test est entièrement décrit. Nous présentons ensuite les mesures effectuées avec des faisceaux d'ions xénon puis oxygène. Certains paramètres de la source d'ions plasma ont ainsi été obtenus. / For more than 45 years, focused ion beams FIB columns based on liquid metal ion sources (Ga) have been used for the development, modification or analysis of nanostructures. Much more recently, less than 10 years ago, plasma sources are integrated in FIBs to meet the needs of failure analysis as well as sample preparation. This plasma FIB market has grown strongly in recent years and is accompanied by a permanent improvement of the specifications of this young technology. Therefore, it is necessary to characterize these sources in order to improve the associated optics. In this thesis, we present the development of a new FIB column working with a plasma ion source, dedicated to the creation of NV centers, as well as the development of a system dedicated to the characterization of the performances of this source.Given the context of this work, the first part of the manuscript is dedicated to the presentation of FIB technology, its operation and its applications. In the second chapter, we present the development of a FIB column dedicated to the implantation of nitrogen ions for the controlled creation of NV color centers in diamonds. We begin by introducing the unique properties of NV centers as well as the usual methods for their creation. Then we present the different steps of the characterization of this FIB column. The implantations carried out during this work have been used for the development of a new application of doped diamonds.In the last chapter of the thesis, we are interested in designing a test bench to obtain the key parameters of the ion source, namely energy dispersion and emittance. The usual methods for measuring these parameters are presented and the operation of the test bench is fully described. Then we then present the measurements made with beams of xenon ions and oxygen ions. Some parameters of the plasma ion source have thus been obtained.

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第18806号 / 理博第4064号 / 新制||理||1585(附属図書館) / 31757 / 京都大学大学院理学研究科地球惑星科学専攻 / (主査)教授 平島 崇男, 教授 大沢 信二, 准教授 河上 哲生 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM

Focused Ion Beam (FIB) is an important analytical and sample modification technique in the field of electron and ion microscopy. It has been widely used in different kinds of applications including semiconductor device failure analysis, material science research, nanoscale 3D tomography, as well as microstructure prototyping and surface modification. Recent developments from the rapid growing industry and our frontier research have posted new challenges on the FIB technology itself. Higher resolution has been realized by state-of-the-art hardware infrastructures and less sample destruction has been achieved by efficient operation recipes. In this doctoral thesis, a study of advanced Focused Ion Beam sample preparation is presented, with the goal to prepare samples with low or no damage. The study is divided into two aspects according to various aspects in the FIB applications: sample damage and in-situ preparation. In the first aspect, sample damage, namely amorphization, ion implantation and FIB milling rate are investigated on crystalline silicon specimens with a gallium FIB tool. To study the ion-beam induced amorphous layer thickness under certain conditions, silicon specimens were prepared by FIB into specific geometry, so that the induced amorphous layer can be imaged and the thickness can be determined quantitatively using Transmission Electron Microscopy (TEM). Atom Probe Tomography (APT) was carried out to study the implanted ion concentration of gallium FIB prepared silicon specimens. In addition, the gallium FIB milling rate was also studied for a silicon substrate using Scanning Electron Microscopy (SEM). These experimental results provide detailed information of beam-sample interactions from the FIB sample preparation. In order to gain a systematic understanding of the processes, as well as to be able to predict the outcome of a specific FIB recipe, a physics model and an adapted algorithm (TRIDYN) based on Binary Collision Approximation (BCA) were used for the simulation of FIB processes. The predicted results based on simulations were compared with experiments. The proposed model was successfully validated by the experimental results, i.e., the TRIDYN algorithm has the capability to provide predictions for the multi- step FIB sample preparation process and the respective recipes. The other aspect involves a novel design of a hardware configuration of a SEM/FIB system add-on to perform in-situ surface modification tasks such as argon ion polishing of specimens. This Beam Induced Polishing System (BIPS) overcomes the disadvantages that some of the ex-situ methods have, and it completes some of the advanced FIB recipes for extremely thin and pristine specimens. In the thesis, the functionality of a BIPS system is explained in detail, and first experimental results are shown to demonstrate the proof of concept of the system. To summarize, this doctoral thesis presents an adapted algorithm, which is validated by experiments, to simulate the multi-step Focused Ion Beam process for recipes of low- damage sample preparation; A novel in-situ experiment system BIPS is also introduced, providing an option to complement SEM/FIB systems for advanced FIB sample preparation recipes.

<p>  </p> <p>Polymer bonded explosives (PBX) are a particle reinforced composite containing a high solids loading of explosive particulates bound in a polymer matrix. Commercially produced energetic particulates contain some percentage of flaws in the form of contaminants, porosity, and preexisting fractures. Additional large-scale porosity within the composite is generated during PBX formulation. The introduction of novel additive manufacturing techniques to the energetics field alters the known composite structure and introduces a porosity variable that has not been fully characterized. Porosity collapse during deformation is believed to be a predominant mechanism for hotspot formation, which dominates shock initiation behaviors. These phenomena are difficult to experimentally characterize due to inherent small spectral and temporal scales, and as such numerical and computational models are relied upon to inform fundamental physics. Experimental characterization of the behaviors of energetic materials during deformation is necessary to better inform computational studies and improve our understanding of hotspot formation mechanisms. </p> <p>This dissertation experimentally evaluates the high-rate deformation of porosity in individual explosive particulates and within the overall composite structure. This has included the development of a novel micromachining technique for pore generation in energetic single crystals using the focused ion beam (FIB), resulting in precise and controllable porosity generation that is easily reproducible in collaboration with computational studies. FIB was shown to be an effective pore generation technique, verified by assessing surface roughness and pore quality compared to contemporary manufacturing methods. Three experimental subsets are evaluated: surface cracks in HMX single crystals, polygonal pores in HMX single crystals, and large-scale porosity variations in mock vibration assisted print (VAP) produced composites of borosilicate glass beads and Sylgard 184® binder. A single stage light gas gun was used to impact the samples at 400 m/s and the impact event and resultant material response were observed in real time using x-ray phase contrast imaging (PCI). Machined surface cracks were shown to have negligible effect on the final fracture behaviors of HMX crystals. In polygonal pores fractures were shown to originate due to stress concentration during impact followed by otherwise expected brittle fracture behaviors. For wedge-like pores, the shockwave culminates on the front face of the pore and contributed to early fracture in some samples as well as a consistent open fracture opposite the impact along the shockwave direction in later stages of impact. For the blunt rectangular-like pores two differing behaviors were observed, wherein either the pore condensed and fracture at the pore was not seen during the impact event or large open fractures formed at the pore corners opposite the shockwave. The variance in response is attributed to the energy of fracture dissipating somewhere else in the material bulk, like the behaviors observed in the milled slot samples. Finally, additively manufactured PBX deformation behaviors were observed to be dominated by the collapse of the existing ordered porosity in the bulk which occurred at an increased rate relative to the bulk material compression. This resulted in a three-stage progression of deformation, consisting of a rapid collapse of large-scale ordered porosity, followed by the densification of the remaining features, and ultimately ending in compaction of the bulk as the impact projectile fully compressed the samples. Future work includes exploration of further FIB produced pore effects on dynamic fractures, evaluation of printed material deformation behaviors at additional rates, as well as application and evaluation of additional VAP printed material formulations.  </p>

[pt] A presença de aminoácidos em cometas e meteoritos levanta questões sobre como estes foram formados em ambientes cósmicos, bem como de que maneira eles foram capazes de sobreviver no espaço sideral; radioresistência é uma informação essencial para prever meias-vidas e avançar os estudos sobre origens da vida. O principal objetivo deste trabalho é determinar, por meio de espectroscopia no infravermelho, as seções de choque de destruição de aminoácidos comuns expostos à radiação de íons e elétrons energéticos. As forças de banda vibracionais (A-values) e a dependência do espectro infravermelho com a temperatura da amostra (10 – 400 K) foram analisadas. Seções de choque de destruição aparente (sigma)d(ap) e rendimentos de sputtering (Y0) para glicina, valina e fenilalanina irradiadas por H+, He+ e Nq+ íons de MeV e elétrons de keV foram medidos. Encontrou-se: i) uma dependência aproximadamente linear entre a seção de choque de destruição aparente e o poder de freamento eletrônico (Se): (sigma)d(ap) = (sigma)d + Y0 /N0 = a Sen (onde n aproximadamente 1) para projéteis de MeV e para amostras à temperatura ambiente; ii) resultados preliminares de σdap para feixes de nitrogênio multi-carregados; e iii) resultados de seção de choque de destruição de valina irradiada por elétrons de keV, bem como sua dependência com a energia de incidência do feixe, e com a espessura e temperatura da amostra. Como contribuição teórica, o modelo CASINO-estendido foi desenvolvido visando descrever a evolução da degradação de matéria orgânica por projéteis carregados, particularmente por feixes de elétrons. Comparadas aos resultados experimentais, as previsões do modelo subestimam o dano causado pelo feixe de elétrons, evidência de que efeitos de sputtering e provavelmente algumas características da amostra (como a estrutura cristalográfica) devem ser incluídos. Como implicações astrofísicas, meias-vidas para valina e fenilalanina irradiadas por raios cósmicos são estimadas em aproximadamente 10 milhões de anos no meio interestelar; da glicina, se irradiadas por vento solar a uma unidade astronômica do Sol, é aproximadamente 3 dias. Visando simular materiais astrofísicos realistas bombardeados por elétrons de keV, a meia-vida de valina envolta por gelos de água e CO2 e depositada sobre silicato é também prevista. / [en] The presence of amino acids in comets and meteorites raises questions about how they have been formed in cosmic environments, as well as how long they can survive in outer space; radioresistance is essential information to predict half-lives and make advances on the origins of life studies. The main objective of the current work is to determine, via infrared spectrometry, destruction cross sections of common amino acids exposed to energetic ion and electron radiation. Before sample irradiation, valine vibrational band strengths and their infrared spectral dependence on temperature (10 – 400 K) were analyzed. Apparent destruction cross sections (sigma)d(ap) and sputtering yields (Y0) for glycine, valine and phenylalanine, irradiated by MeV H+, He+ and Nq+ ions and keV electrons, were measured. From experimental data: i) an approximately linear dependence between the apparent destruction cross section and the electronic stopping power (Se) is found: (sigma)d(ap) = (sigma)d + Y0 /N0 = a Sen (where n approximately 1) for MeV projectiles and for samples at room temperature; ii) (sigma)d(ap) preliminary results relative to multi-charged nitrogen ion beams are discussed; and iii) destruction cross section of valine irradiated by keV electrons, as well as its dependence on incident beam energy, on sample thickness and on sample temperature are presented. As a theoretical contribution, the evolution of organic matter damage by charged projectiles, particularly for electron beams, the CASINO-extended model was developed. When compared to experimental results, the model predictions underestimate the damage caused by electron beams, evidence that sputtering and probably some sample characteristics (as crystallographic structure) are involved. As astrophysical implications, cosmic ray half-lives for valine and phenylalanine are estimated to be about 10 million years in the interstellar medium; solar wind half-life at 1 au from the Sun is approximately 3 days for glycine. Aiming to simulate realistic astrophysical materials bombarded by keV electrons, the half-life of valine embedded into water and CO2 ices over a silicate substrate is also predicted.

Physical vapor deposition (PVD) refers to the removal of atoms from a solid or a liquid by physical means, followed by deposition of those atoms on a nearby surface to form a thin film or coating. Various approaches and techniques are applied to release the atoms including thermal evaporation, electron beam evaporation, ion-driven sputtering, laser ablation, and cathodic arc-based emission. Some of the approaches are based on a plasma discharge, while in other cases the atoms composing the vapor are ionized either due to the release of the film-forming species or they are ionized intentionally afterward. Here, a brief overview of the various PVD techniques is given, while the emphasis is on sputtering, which is dominated by magnetron sputtering, the most widely used technique for deposition of both metallic and compound thin films. The advantages and drawbacks of the various techniques are discussed and compared.

Die dreidimensionale Mikrostruktur, welche bei der Oberflächenkristallisation von Glaskeramiken entsteht, wird mittels einer neuartigen Methode zur Präparation von abgesenkten Probenoberflächen untersucht. Diese Initialkantensektionierungsmethode, welche auf der Erzeugung von Scharten in der Probenoberfläche und anschließender Glanzwinkelionenstrahlerosion basiert, erlaubt das rapide Freilegen von großflächigen Schichten in wohldefinierten Tiefen unterhalb der ursprünglichen Probenoberfläche. In dieser Dissertation werden mehrere Variationen der Technik durch Kombination von Laserablation, Ionenbreit- sowie Ionenfeinstrahlerosion untersucht und miteinander verglichen. Die in Bezug auf Schnittgeometrie und Probengüte relevanten, experimentellen Parameter werden bestimmt und bewertet. Ein Modell zur Beschreibung der zeitlichen Evolution der Probengeometrie während des Erosionsvorgangs wird auf Grundlage von Simulationen und analytischen Näherungen aufgestellt und mit experimentellen Ergebnissen verglichen. Schließlich wird die Initialkantensektionierungsmethode mit Elektronenrückstreubeugung kombiniert um Wachstumseffekte bei der Oberflächenkristallisation von Diopsid- und Ba2TiSi2O8-Fresnoitglaskeramiken zu untersuchen.:1 Introduction 1.1 Motivation 1.2 Aims and Objectives 2 Literature Review 2.1 Sample Preparation for Electron Backscatter Diffraction Studies 2.2 Serial Sectioning Methods 2.3 Microstructure Characterization of Glass Ceramics using EBSD 2.4 Interim Conclusion 3 Theory 3.1 Erosion of a Surface Under Ion Bombardment 3.1.1 Sputtering 3.1.2 Kinetic Theory of Surface Evolution 3.1.3 Numerical Simulation of Surface Erosion 3.1.4 Erosion of a Surface With Initial Notches 3.2 Electron Backscatter Diffraction 3.2.1 Measurement Principle 3.2.2 Representation of Orientations and Texture 4 Methods and Materials 4.1 Sample Preparation and Processing 4.2 Surface Metrology 4.3 Microstructure Analysis 4.4 Materials 5 Erosion of Surfaces With Initial Notches 5.1 Evaluation of Surface Processing Methods 5.1.1 Notch Creation 5.1.2 Terrace Formation by Glancing-Angle Ion Beam Erosion 5.2 Surface Properties in the Terrace Region 5.2.1 Terrace Roughness 5.2.2 Ion Beam Induced Amorphization 5.3 Evolution of Surface Geometry 5.3.1 Linear Model 5.3.2 Simulations 5.3.3 Experimental Results 5.4 Discussion 5.4.1 Sample Processing 5.4.2 Sample Quality 5.4.3 Kinetic Model of Surface Evolution 6 Depth-Resolved Microstructure Characterization Using Initial Notches 6.1 Diopside 6.2 Ba2TiSi2O8 fresnoite (BTS) 6.3 Discussion 6.3.1 Methodological Aspects of Initial Notch Sectioning 6.3.2 Microstructure Analysis on Surface-Crystallized Glass Ceramics 7 Summary and Outlook / Three-dimensional microstructures resulting from surface crystallization of glass ceramics are studied using a novel sample sectioning method. Based on the creation of notches on the sample surface and subsequent glancing-angle ion beam erosion, initial notch sectioning enables the rapid excavation of large subsurface layers at well-defined depths. In this thesis, several variations of this technique using different combinations of laser ablation, broad and focused ion beam erosion are realized and compared to each other. Relevant parameters controlling the section geometry and quality are determined. A model of the surface evolution kinetics is developed using simulations and analytical estimates, which is compared to experimental results. Finally, initial notch sectioning in combination with electron backscatter diffraction is applied to elucidate growth phenomena in the surface crystallization of diopside and Ba2TiSi2O8 fresnoite glass ceramics.:1 Introduction 1.1 Motivation 1.2 Aims and Objectives 2 Literature Review 2.1 Sample Preparation for Electron Backscatter Diffraction Studies 2.2 Serial Sectioning Methods 2.3 Microstructure Characterization of Glass Ceramics using EBSD 2.4 Interim Conclusion 3 Theory 3.1 Erosion of a Surface Under Ion Bombardment 3.1.1 Sputtering 3.1.2 Kinetic Theory of Surface Evolution 3.1.3 Numerical Simulation of Surface Erosion 3.1.4 Erosion of a Surface With Initial Notches 3.2 Electron Backscatter Diffraction 3.2.1 Measurement Principle 3.2.2 Representation of Orientations and Texture 4 Methods and Materials 4.1 Sample Preparation and Processing 4.2 Surface Metrology 4.3 Microstructure Analysis 4.4 Materials 5 Erosion of Surfaces With Initial Notches 5.1 Evaluation of Surface Processing Methods 5.1.1 Notch Creation 5.1.2 Terrace Formation by Glancing-Angle Ion Beam Erosion 5.2 Surface Properties in the Terrace Region 5.2.1 Terrace Roughness 5.2.2 Ion Beam Induced Amorphization 5.3 Evolution of Surface Geometry 5.3.1 Linear Model 5.3.2 Simulations 5.3.3 Experimental Results 5.4 Discussion 5.4.1 Sample Processing 5.4.2 Sample Quality 5.4.3 Kinetic Model of Surface Evolution 6 Depth-Resolved Microstructure Characterization Using Initial Notches 6.1 Diopside 6.2 Ba2TiSi2O8 fresnoite (BTS) 6.3 Discussion 6.3.1 Methodological Aspects of Initial Notch Sectioning 6.3.2 Microstructure Analysis on Surface-Crystallized Glass Ceramics 7 Summary and Outlook

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Magnetoelectricity (ME) is a physical property that results from an exchange between polar (electric dipole) and spin (magnetic dipole) subsystem: i.e., a change in polarization (P) with application of magnetic field (H), or a change in magnetization (M) with applied electric field (E). Magnetoelectricity can be found both in single phase and composite materials. Compared with single phase multiferroic materials, composite multiferroics have higher ME effects. Through a strictive interaction between the piezoelectricity of the ferroelectric phase and the magnetostriction of the ferromagnetic phase, said multiferroic composites are capable of producing relatively large ME coefficients. This Dissertation focused on the deposition and characterization of two-phase composite magnetoelectric thin films. First, single phase ferroelectric thin films were studied to improve the multiferroic properties of the composite thin films. Then structural, ferroelectric, ferromagnetic, and magnetoelectric properties of composite thin films were researched. Finally, regular nano-array composite films were deposited and characterized. First, for single phase ferroelectric thin films, the phase stability was controlled by epitaxial engineering. Because ferroelectric properties are strongly related to their crystal structure, it is necessary to study the crystal structures in single phase ferroelectric thin films. Through constraint of the substrates, the phase stability of the ferroelectric thin films were able to be altered. Epitaxial thin-layers of Pb(Fe1/2Nb1/2)O3 (or PFN) grown on (001), (110), and (111) SrTiO3 substrates are tetragonal, orthorhombic, and rhombohedral respectively. The larger constraint stress induces higher piezoelectric constants in tetragonal PFN thin film. Epitaxial thin-layers of Pb(Zr0.52Ti0.48)O3 (or PZT) grown on (001), (110), and (111) SrTiO3 substrates are tetragonal, monoclinic C, and rhombohedral respectively. Enhanced ferroelectric properties were found in the low symmetry monoclinic phase. A triclinic phase in BFO was observed when it was deposited on tilted (001) STO substrates by selecting low symmetry (or interim) orientations of single crystal substrates. Then, in two phase composite magnetoelectric thin films, the morphology stability was controlled by epitaxial engineering. Because multiferroic properties are strongly related to the nano-structures of the composite thin films, it is necessary to research the nano-structures in composite thin films. Nano-belt structures were observed in both BaTiO3-CoFe2O4 and BiFeO3-CoFe2O4 systems: by changing the orientation of substrates or annealing condition, the nano-pillar structure could be changed into nano-belts structure. By doing so, the anisotropy of ferromagnetic properties changes accordingly. The multi-ferroic properties and magnetoelectric properties or (001), (110) and (111) self-assembled BiFeO3-CoFe2O4 nano-composite thin film were also measured. Finally, the regular CoFe2O4-BiFeO3 nano-array composite was deposited by pulsed laser deposition patterned using a focused ion beam. Top and cross-section views of the composite thin film showed an ordered CoFe2O4 nano-array embedded in a BiFeO3 matrix. Multiferroic and magnetoelectric properties were measured by piezoresponse force microscopy and magnetic force microscopy. Results show (i) switching of the magnetization in ferromagnetic CoFe2O4 and of the polarization in ferroelectric BiFeO3 phases under external magnetic and electric field respectively, and (ii) changes of the magnetization of CoFe2O4 by applying an electric field to the BiFeO3 phase. / Ph. D.