Thesis (M.S. in Chemistry)--University of California, Berkeley, Jan. 1961. / "UCRL-9372." TID-4500(15th ed.). Includes bibliographical references (leaf 31).

Inaug.-diss.--Berlin. / Lebenslauf.

Thesis (M.S.)--University of Wisconsin--Madison, 1964. / eContent provider-neutral record in process. Description based on print version record. Bibliography: l. 49-50.

Thesis (M.Sc.)--York University, 2005. Graduate Programme in Chemistry. / Typescript. Includes bibliographical references (leaves 87-91). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://wwwlib.umi.com/cr/yorku/fullcit?pMR11941

Th.--Méd.--Montpellier, 1910-1911. / Montpellier, 1910-1911. N ° 101.

Th.--Méd.--Paris, 1899-1900. / Paris, 1899-1900, tome 47, n ° 75.

L'objectif de ces travaux concerne la synthèse de matériaux thermoélectriques, pouvant être utilisés pour la réalisation de modules à transfert de chaleur, par électrochimie en mode pulsé. Cette forme avancée de l électrodéposition est souvent citée dans la littérature comme susceptible d améliorer la morphologie des dépôts. Les matériaux visés sont ceux de la famille du tellurure de bismuth.La première partie de ce travail a été consacrée à l étude des différents phénomènes fondamentaux intervenant dans la synthèse pulsée. Le type de nucléation a été déterminé, se révélant être de type instantané 3D. L identification des phénomènes de transfert de charge et de matière a permis de définir les paramètres d impulsion conduisant à un dépôt. La morphologie a été optimisée par l application de paramètres d impulsions adéquats.La synthèse de films de Bi2Te3 de 5 m d épaisseur a ensuite été réalisée. Des dépôts possédant un excès de bismuth ou un excès de tellure ont été obtenus en modulant à la fois les paramètres d impulsion et l électrolyte. La mesure des propriétés thermoélectriques a mis en évidence que l association du mode pulsé et d un traitement thermique permet d obtenir des dépôts plus performants qu'en mode continu. La dernière partie s est intéressée à la synthèse en mode pulsé du composé ternaire à base d antimoine. L étude de la composition a montré qu'il est nécessaire d augmenter la quantité de bismuth et d antimoine dans l électrolyte pour obtenir la stœchiométrie Bi0,5Sb1,5Te3. La mesure des propriétés physiques a mis en évidence une conductivité de type p directement après synthèse ainsi que l intérêt du mode pulsé pour la résistivité électrique des films. / The objective of this work is the pulsed electrodeposition of thermoelectric materials, which can be used for the manufacture of heat transfer modules. This advanced form of electrodeposition is often mentioned in the literature to improve the morphology of deposits. The aimed materials are compounds of bismuth telluride family.The first part of this work has been dedicated to the study of fundamental phenomena operating in pulse mode. The nucleation type was determined, which is 3D instantaneous type. The charge and mass transfer phenomena were identified, allowing the definition of an optimal deposition range. Finally, the parameters giving the optimal morphology have been determined.The syntheses of 5 m thickness Bi2Te3 films have been carried out. Deposits having an excess of bismuth or an excess of tellurium were obtained by varying pulse parameters and the electrolyte composition. Thermoelectric properties measure underlined that the association of pulse mode and annealing allows to obtaining deposits more efficient than in continuous mode.The last part has been dedicated to the synthesis in pulse mode of antimony ternary compounds. The study of the composition showed that it is necessary to increase the quantity of bismuth and antimony in the electrolyte to obtain the stoichiometry Bi0.5Sb1.5Te3. The measure of physic properties evidenced p-type conductivity directly after synthesis as well as the interest of pulse mode to improve the electrical resistivity of films

The thesis entitled "Layered Oxides and Phosphates of Bismuth: New Structural Types and Related Properties" consists of three parts and six chapters. It begins with an introductory note providing a brief overview of the existing literature on bismuth based layered oxides. Part A of the thesis describes novel variants of the Aurivillius, Scheelite and Fluorite related phases with special emphasis on photocatalytic behavior of these materials. Chapter 1 describes two new compounds, LiBi4Nb3O14 and LiBi4Ta3O14 characterized by single crystal X-ray diffraction to depict a unique structure, which have similarities with both an ideal Aurivillius phase and a typical hexagonal tungsten bronze. Photo-degradation of a wide range of water pollutants, which include commonly, used dyes in textile industry and phenols suggest selectivity of LiBi4Nb3O14 towards hydroxyl group containing aromatic compounds. Chapter 2, Section 1 presents the structure of BaBi2Mo4O16 as a new compound among Scheelites, which shows high selectivity towards photo-degradation of non- chloro-containing aromatic systems. Further, the degradation rates are found to be significantly higher than the commercial TiO2 catalyst for nitro and methyl phenols. The solid solution, BaBi2Mo4-xWxO16 (0.25 ≤ x ≤ 1) has been analyzed to obtain insights into the compositional aspects. Section 2 has a detailed discussion on the structural stability of the Scheelite BaBi2Mo4O16 upon substitution of divalent cations, Ca, Sr and Pb at the barium site. The potential of these compounds as photocatalytic materials has been investigated. Chapter 3 describes a detailed kinetic analysis along with a single crystal X-ray structure determination of Ba2Bi24Mo10O68. Substitution at the Bi site by Ba and La results in differences in photocatalytic activity. All variants are observed to show specificity towards nitro- substitution at the ortho- position in phenols. Chapter 4 is a re-determination of the crystal structures of the triclinic polymorphs of BiNbO4 and BiTaO4 since one of the earlier reports is on a twinned crystal with large, unacceptable thermal ellipsoids and the other is a powder data -based Rietveld refinement of this model. Further BiNbO4 has been investigated to evaluate selectivity in photo degradation of dyes. In Part B, an attempt to correlate the crystal structure with relaxor ferroelectric behavior is outlined. Chapter 5 investigates a bismuth based tetratungsten bronze (TTB) relaxor material for the first time. Single crystal X-ray diffraction studies on the composition, x = 0.77 of the solid solution, Ba5x/2Bi(1-x)5/3Nb5O15 (0.52 ≤ x ≤ 0.8) depicts disorder in the occupancies of barium and bismuth atoms which is suggested to be the possible origin for relaxor behavior. Dielectric measurements correlate the structural features. Part C consists of a structure-based analysis on possible correlations with ionic conductivity. Chapter 6 describes two new crystal structures, Bi17P8O45.5 and Bi20P8O50, and the evolution of the series, Bi16+xP8O45+(3x-2)/2 (0.7 ≤ x ≤ 4.0). A rationale for the low ionic conductivity exhibited in these materials is arrived at from the arrangement of atoms in the crystal structure. Appendix A consists of a description of the crystal structure and ionic conductivity of Bi3W2O10.5.

This paper is a study of the exchange of bismuth tetra-iodide and bismuth ions in an ion-precipitate system.

No description available.