Esta pesquisa analisa a história dos modelos atômicos no início do século XX a partir das contribuições de Joseph John Thomson, Hantaro Nagaoka, Ernest Rutherford, John William Nicholson e Niels Bohr e seus contemporâneos, enfatizando as explicações desde a Física Clássica até a introdução da Teoria Quântica. A tese apresenta uma introdução e oito capítulos. O primeiro capítulo procura dar conta do “estado da arte” antes da proposição dos modelos discutidos. Neste capítulo enfatizamos questões que se localizam no campo da ciência clássica, sem mergulhar no campo da teoria quântica nascente. Na continuidade, apresentamos seis capítulos, cronologicamente organizados com uma breve biografia de cada um dos cientistas mencionados e o detalhamento das idéias e dos episódios científicos que levaram às publicações que apresentaram seus modelos pela primeira vez. A publicação dos modelos de átomo quantizados teve grande impacto e suscitou muitos debates, o que nos levou a produzir o capítulo sete tratando especificamente desses embates. Para concluir no capítulo oito apresentamos algumas considerações sobre a integração das diversas trilhas investigativas que levam à publicação dos modelos atômicos discutidos; ao trabalho nas fronteiras de campos investigativos diversos; à intrincada dinâmica de poder entre campos, cientistas e publicações; e à afirmação de novos campos. / The present research examines the history of atomic models in the early twentieth century dealing with the contributions of Joseph John Thomson, Hantaro Nagaoka, Ernest Rutherford, John William Nicholson and Niels Bohr and his contemporaries. It emphasizes the explanations from the classical physics till the introduction of the Quantum Theory. This thesis presents an introduction and eight chapters. Chapter 1 presents the investigations which took place before the proposition of the models pointed out in the first paragraph. This chapter emphasizes the classical science, without diving into the quantum explanations. The next six chapters present a chronological sequence of biographies, ideas and publications and discuss the atomic models proposed by the quoted scientists. The publication of the papers on the quantized atom models had great impact and caused many debates, which led us to produce a specific chapter dealing with such subject. . In conclusion, the chapter eight presents some considerations about the integration of the investigative trails that led to the publication of the atomic models discussed, the work on investigative borders fields, the intricate dynamics of power between fields, scientists and publications, and the assertion of new fields.

In this thesis, energy levels, lifetimes, oscillator strengths and transition probabilities of Mg VII have been calculated. The Hartree-Fock (HF) and Multiconfiguration Hartree-Fock (MCHF) methods were used in the calculations of these atomic properties. We have included relativistic operators mass correction, spin-orbit interaction, one body Darwin term and spin-other-orbit interaction in the Breit-Pauli Hamiltonian. The configurations, (1s2)2s22p2, 2s2p3,2p4, 2s22p3s, 2s22p3p,2s2p2(4P)3s and 2s22p3d which correspond to 52 fine-structure levels, were included in the atomic model for the Mg VII ions. The present results have been compared with NIST compilation and other theoretical results, and generally a good agreement was found.

Esta pesquisa analisa a história dos modelos atômicos no início do século XX a partir das contribuições de Joseph John Thomson, Hantaro Nagaoka, Ernest Rutherford, John William Nicholson e Niels Bohr e seus contemporâneos, enfatizando as explicações desde a Física Clássica até a introdução da Teoria Quântica. A tese apresenta uma introdução e oito capítulos. O primeiro capítulo procura dar conta do “estado da arte” antes da proposição dos modelos discutidos. Neste capítulo enfatizamos questões que se localizam no campo da ciência clássica, sem mergulhar no campo da teoria quântica nascente. Na continuidade, apresentamos seis capítulos, cronologicamente organizados com uma breve biografia de cada um dos cientistas mencionados e o detalhamento das idéias e dos episódios científicos que levaram às publicações que apresentaram seus modelos pela primeira vez. A publicação dos modelos de átomo quantizados teve grande impacto e suscitou muitos debates, o que nos levou a produzir o capítulo sete tratando especificamente desses embates. Para concluir no capítulo oito apresentamos algumas considerações sobre a integração das diversas trilhas investigativas que levam à publicação dos modelos atômicos discutidos; ao trabalho nas fronteiras de campos investigativos diversos; à intrincada dinâmica de poder entre campos, cientistas e publicações; e à afirmação de novos campos. / The present research examines the history of atomic models in the early twentieth century dealing with the contributions of Joseph John Thomson, Hantaro Nagaoka, Ernest Rutherford, John William Nicholson and Niels Bohr and his contemporaries. It emphasizes the explanations from the classical physics till the introduction of the Quantum Theory. This thesis presents an introduction and eight chapters. Chapter 1 presents the investigations which took place before the proposition of the models pointed out in the first paragraph. This chapter emphasizes the classical science, without diving into the quantum explanations. The next six chapters present a chronological sequence of biographies, ideas and publications and discuss the atomic models proposed by the quoted scientists. The publication of the papers on the quantized atom models had great impact and caused many debates, which led us to produce a specific chapter dealing with such subject. . In conclusion, the chapter eight presents some considerations about the integration of the investigative trails that led to the publication of the atomic models discussed, the work on investigative borders fields, the intricate dynamics of power between fields, scientists and publications, and the assertion of new fields.

Esta pesquisa analisa a história dos modelos atômicos no início do século XX a partir das contribuições de Joseph John Thomson, Hantaro Nagaoka, Ernest Rutherford, John William Nicholson e Niels Bohr e seus contemporâneos, enfatizando as explicações desde a Física Clássica até a introdução da Teoria Quântica. A tese apresenta uma introdução e oito capítulos. O primeiro capítulo procura dar conta do “estado da arte” antes da proposição dos modelos discutidos. Neste capítulo enfatizamos questões que se localizam no campo da ciência clássica, sem mergulhar no campo da teoria quântica nascente. Na continuidade, apresentamos seis capítulos, cronologicamente organizados com uma breve biografia de cada um dos cientistas mencionados e o detalhamento das idéias e dos episódios científicos que levaram às publicações que apresentaram seus modelos pela primeira vez. A publicação dos modelos de átomo quantizados teve grande impacto e suscitou muitos debates, o que nos levou a produzir o capítulo sete tratando especificamente desses embates. Para concluir no capítulo oito apresentamos algumas considerações sobre a integração das diversas trilhas investigativas que levam à publicação dos modelos atômicos discutidos; ao trabalho nas fronteiras de campos investigativos diversos; à intrincada dinâmica de poder entre campos, cientistas e publicações; e à afirmação de novos campos. / The present research examines the history of atomic models in the early twentieth century dealing with the contributions of Joseph John Thomson, Hantaro Nagaoka, Ernest Rutherford, John William Nicholson and Niels Bohr and his contemporaries. It emphasizes the explanations from the classical physics till the introduction of the Quantum Theory. This thesis presents an introduction and eight chapters. Chapter 1 presents the investigations which took place before the proposition of the models pointed out in the first paragraph. This chapter emphasizes the classical science, without diving into the quantum explanations. The next six chapters present a chronological sequence of biographies, ideas and publications and discuss the atomic models proposed by the quoted scientists. The publication of the papers on the quantized atom models had great impact and caused many debates, which led us to produce a specific chapter dealing with such subject. . In conclusion, the chapter eight presents some considerations about the integration of the investigative trails that led to the publication of the atomic models discussed, the work on investigative borders fields, the intricate dynamics of power between fields, scientists and publications, and the assertion of new fields.

Bioactive glasses are a class of synthetic inorganic material that have wide orthopedics, dentistry, tissue engineering and other biomedical applications. The origin of the bioactivity is closely related to the atomic structures of these novel glass materials, which otherwise lack long range order and defies any direct experimental measurements due to their amorphous nature. The structure of bioactive glasses is thus essential for the understanding of bioactive behaviors and eventually rational design of glass compositions. In this dissertation, molecular dynamics (MD) and reverse monte carlo (RMC) based computer simulations have been used to systematically study the atomic structure of three classes of new bioactive glasses: strontium doped 45S5 Bioglass®, ZnO-SrO containing bioactive glasses, and Cao-MgO-P2O5-SiO2 bioactive glasses. Properties such as ionic diffusion that are important to glass dissolution behaviors are also examined as a function of glass compositions. The accuracy of structure model generated by simulation was validated by comparing with various experimental measurements including X-ray/neutron diffraction, NMR and Raman spectroscopy. It is shown in this dissertation that atomistic computer simulations, when integrated with structural and property characterizations, is an effective tool in understanding the structural origin of bioactivity and other properties of amorphous bioactive materials that can lead to design of novel materials for biomedical applications.

In this work, the relationship between grain boundary crystallography and grain boundary atomic structure is examined, using [1 0 0] - symmetric tilt grain boundaries in nickel. The structural unit model is used as a benchmark to evaluate the atomic structure description capacities of an emerging structural descriptor, the local environment representation, which itself is a refinement of the also-emergent Smooth Overlap of Atomic Positions (SOAP) descriptor. We show that the local environment representation encodes both the information of the structural unit model and additional information, such as distortion in the structural units and the arrangement of the structural units at the interface. The use of the local environment representation permits the use of a visualization tool known as SPRING to represent structural similarities between grain boundaries. With the SPRING representation, we produce objective evidence of a relationship between crystallography and atomic structure, at least for [1 0 0] - symmetric tilt grain boundaries.

Kesterite sind Verbindungshalbleiter aus ungiftigen und vergleichsweise häufigen Elementen, die als Absorber in Dünnschichtsolarzellen genutzt werden können. Häufig wird ihre Zusammensetzung durch Variation der Stöchiometrie oder Legierung verändert, um ihre Effizienz marktfähig zu machen. Die langreichweitigen, strukturellen Einflüsse dieser Methoden sind wohl bekannt. Erkenntnisse aus den ähnlichen Chalcopyriten legen jedoch nahe, dass die lokale atomare Struktur sich nicht im gleichen Maße ändert. In der vorliegenden Arbeit wurde daher Extended X-ray Absorption Fine Structure spectroscopy (EXAFS) verwendet, um Veränderungen in der lokalen Struktur von nicht stöchiometrischen oder legierten Pulverproben und Dünnschichten auf winzigen Skalen zu analysieren. Es zeigt sich, dass Kesterite viele Eigenschaften ihrer lokalen Struktur auch über signifikante Zusammensetzungsveränderungen hinaus beibehalten. Trotzdem wird die Wichtigkeit dieser Untersuchungen deutlich. So kann unter anderem der direkte Einfluss der lokalen Struktur auf die Bandlücke gezeigt werden. / Kesterite type materials are researched for their ability to form thin film solar cell absorbers from earth abundant and non-toxic elements. Main routes to increase their efficiencies to the level of competing materials include compositional variations such as deviations from stoichiometry and alloying. While the long range structural impacts of these methods are well known, similarities with chalcopyrites indicate that the local atomic structure will not change on the same order of magnitude. This thesis hence employs low temperature Extended X-ray Absorption Fine Structure spectroscopy (EXAFS) measurements on off-stoichiometric or alloyed powder samples and thin films, to reveal the small changes in local atomic environments. It is shown that kesterites tend to keep many aspects of their local atomic structure despite major compositional changes. Yet, both the impact of these small changes on band gap energy as well as further value of probing the local atomic structure of kesterite thin films are demonstrated.

In this thesis, the morphology and electric potential of pristine and gold covered surfaces with the fluorite structure are investigated by non-contact atomic force microscopy (NC-AFM) and Kelvin probe force microscopy (KPFM). The pristine (111) surface of calcium difluride is prepared by cleaving. Cleavege ledges are composed of short alternating type I and type II steps having different atomic structures and polarities. With respect to the stoichiometric terrace, the surface potential is slightly reduced at ledges predominately composed of type I steps, while the potential of ledges predominantly composed of type II steps is significantly higher. Pristine (111) surfaces of ceria single crystals and ceria thick films are prepared by repeated cycles of sputtering and annealing. Annealing bulk samples at 1100 K results in small terraces with rounded ledges and steps with predominantly one O-Ce-O triple layer height while annealing at 1200 K produces well-ordered straight step edges in a hexagonal motif and step bunching. The morphology and topographic details of films are similar, however, films are destroyed upon heating above 1100 K. NC-AFM and KPFM images exhibit uniform and atomically perfect terraces on a single crystal surface while films exhibit significant inhomogeneities even for best possible preparation conditions. Applying X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectroscopy (TOF-SIMS), a significant contamination of the bulk ceria sample with fluorine within the first 5 nm below the surface is found while a possible fluorine contamination of films is below the detection limits. After deposition of gold, a surprisingly strong interaction of gold adatoms to the (111) surface of bulk ceria is found. The pinning of individual adatoms to one specific surface site and the stability against sintering for annealing temperatures up to 520 K is discussed considering the fluorine contamination of bulk ceria samples. Additionally nanoscale gold clusters supported on ceria are fully characterized by employing elaborate NC-AFM and KPFM experiments gaining detailed information on their shape, crystalinity, epitaxy and binding to the substrate.

Ce travail de thèse est consacré à l’étude de nanotubes géo-inspirés des nanotubes d’imogolite naturels présents dans certains sols et à celle des propriétés dynamiques de l’eau dans ces objets. Les objets étudiés, de stoechiométrie Ge(Si)Al₂O₇H₄ et Ge(Si)Al₂O₆CH₆, sont des nanotubes d’aluminosilicate et d’aluminogermanate dont la paroi interne est tapissée soit de groupements hydroxyles, hydrophiles, soit de groupements méthyles, hydrophobes. Dans le premier chapitre de ce manuscrit, nous présentons un état des connaissances sur ces nanotubes et nous introduisons la thématique de l’eau confinée. Le second chapitre est consacré à l’analyse de la structure des nanotubes sur la base d’expériences de diffusion des rayons X sur poudre. Nous y introduisons une nouvelle méthodologie, fondée sur l’utilisation des symétries hélicoïdales et la minimisation d’une énergie semi-empirique, permettant de réduire la détermination d’une structure tubulaire complexe à l’évaluation de quelques paramètres géométriques. Grâce à cette procédure, nous déterminons la structure des nanotubes d’aluminosilicate et d’aluminogermanate méthylés et hydroxylés. En particulier, un mode d’enroulement différent pour les nanotubes méthylés et hydroxylés est mis en évidence. Dans le troisième chapitre, nous présentons l’étude expérimentale des transformations en température des nanotubes d’aluminogermanate hydroxylés, jusqu’à 1000°C, grâce à une approche multitechnique associant la spectroscopie d’absorption X in situ aux seuils K de l’aluminium et du germanium, la spectroscopie RMN, la spectroscopie infrarouge et la diffusion des rayons X. Le quatrième chapitre est consacré à l’étude de la dynamique de l’eau dans les nanotubes d’aluminogermanate hydroxylés et méthylés, par diffusion inélastique des neutrons. Dans le cas des nanotubes hydroxylés, les expériences sont analysées à la lumière de simulations de dynamique moléculaire. Nous montrons que l’eau liée à la paroi interne des nanotubes présente une structuration originale et que les dynamiques de l’eau et du nanotube sont fortement corrélées. / This thesis focuses on the investigation of nanotubes geo-inspired from natural imogolite nanotubes present in some soils and on the dynamical properties of water confined in these objects. These objects with nominal stoichiometry Ge(Si)Al₂O₇H₄ and Ge(Si)Al₂O₆CH₆, are aluminosilicate and aluminogermanate nanotubes whose inner wall is covered with either hydrophilic hydroxyl groups or hydrophobic methyl groups. In the first chapter of this manuscript, we present a state of knowledge on these nanotubes and introduce the topic of confined water. The second chapter is dedicated to the analysis of the structure of nanotubes thanks to X-ray powder scattering experiments. We introduce a new methodology, based on the use of helical symmetries and on the minimization of semi-empirical energy, which reduces the determination of a complex tubular structure to the evaluation of some geometric parameters. With this procedure, we solve the structure of both methylated and hydroxylated aluminosilicate and aluminogermanate nanotubes. In particular, a different rolling mode is highlighted for methylated and hydroxylated nanotubes. In the third chapter, we present the experimental study of the thermal transformations of hydroxylated aluminogermanate nanotubes, up to 1000°C. This work is the result of a multi-technical approach combining in situ X-ray absorption spectroscopy at the K thresholds of aluminium and germanium, NMR spectroscopy, infrared spectroscopy and X-ray scattering. The fourth chapter focuses on the study of water dynamics in hydroxylated and methylated aluminogermanate nanotubes by inelastic neutron scattering. For hydroxylated nanotubes, experiments are analyzed in the light of molecular dynamics simulations. We show that the water layer bound to the inner wall of the nanotubes presents an original structure and that the dynamics of water molecules and of the nanotube are strongly correlated.

A group theoretic approach to Layzer's 1/2 expansion method is explored. In part this builds on earlier work of Wulfman(2), of Moshinsky et al(l4), and of Sinanoglu, Herrick(lS), and Kellman (16) on second row atoms. I investigate atoms with electrons in the 3s-3p-3d shell and find: 1. Wulfman's constant of motion accurately predicts configuration mixing for systems with two to eight electrons in the 3s-3p subshell. 2. The same constant of motion accurately predicts configuration mixing for systems with two electrons in the 3s-3p-3d shell. 3. It accurately predicts configuration mixing in systems of high angular momentum L and of high spin angular momentum S containing three electrons in the 3s-3p-3d shell, but gives less accurate results when L and S are both small. I also show how effective nuclear charges may be calculated by a group theoretical approach. In addition I explore several new methods for expressing electron repulsion operators in terms of operators of the 80(4,2) dynamical group of one - electron atoms.