Abstract Mineralogical-mineral chemical characterisation of Nb-Ta-bearingassemblages from the Stripåsen granitic pegmatite, NorbergJens Henriksson The occurrence of Nb-Ta-bearing minerals has earlier been briefly documented inthe Stripåsen granitic pegmatite, Norberg, central Bergslagen. This report describesthe background, preparation and basic characterisation of sampled Nb-Ta-bearingmineral assemblages from this pegmatite. These comprise (Y,REE,U,Th)-(Nb,Ta,Ti)-oxides of mainly a tantalum-dominated A 2-m B 2 X 6-w Y 1-n -type, belonging to the pyrochloresupergroup. The major primary mineral is suggested to have been afluorcalciomicrolite, ideally (Ca,Na,☐) 2 Ta 2 O 6 F. In association with abundant fractureformation related to metamictisation of the microlite minerals, they are interpreted tohave been variably altered by late-stage fluids. Thus, the system has beenextensively modified after the primary crystallisation of the pegmatite melt. Besidesthese (Y,REE,U,Th)-(Nb,Ta,Ti)-oxides, monazite-(Ce) ((Ce, LREE)PO 4 ), nativebismuth (Bi) and presumably radiogenic galena (PbS) were identified. The sampleshave mainly been studied by means of scanning-electron-microscopy with energydispersive spectroscopy (SEM-EDS), utilising reflected polarised light microscopy asa complementary tool. The study was done within the framework of the EU-supported FRAME-project which is focused on a selection of metals and minerals,among others niobium (Nb) and tantalum (Ta). / Sammanfattning Mineralogisk-mineralkemisk karakterisering av Nb-Ta-förande associationerfrån Stripåsenpegmatiten, NorbergJens Henriksson Förekomsten av Nb-Ta-förande mineral har tidigare dokumenteras iStripåsenpegmatiten, Norberg, centrala Bergslagen. Här redogörs för bakgrund,provförberedelse och grundläggande karakterisering av provtagna Nb-Ta-förandemineralassociationer från denna pegmatit. Proven som undersökts innehåller(Y,REE,U,Th)-(Nb,Ta,Ti)-oxider av främst tantaldominerad A 2-m B 2 X 6-w Y 1-n -typtillhörande pyroklorsupergruppen. Den huvudsakliga primära fasen tolkas ha varit enfluorkalciomikrolit, idealiskt (Ca,Na,☐) 2 Ta 2 O 6 F. I anslutning till rikligt förekommandesprickor som är relaterade till omfattande metamiktisering har mikroliternaomvandlats i varierande grad av sena fluider. Systemet har alltså förändrats kraftigtefter den primära kristallisationen av pegmatitsmältan. Förutom (Y,REE,U,Th)-(Nb,Ta,Ti)-oxider identifierades monazit-(Ce) ((Ce,LREE)PO 4 ), gedigen vismut (Bi)och vad som sannolikt är radiogen blyglans (PbS). Provmaterialet har huvudsakligenundersökts med genom svepelektronmikroskopi med energidispersiv spektroskopi(SEM-EDS), varvid malmmikroskopi har använts som ett kompletterande verktyg.Studien gjordes inom ramverket för det EU-stödda FRAME-projektet som blandannat fokuserar på förekomster av de kritiska och konfliktrelaterade metallerna niob(Nb) och tantal (Ta).

This project was ordered by Sandvik Materials Technology and was performed by a group of students at Uppsala university. The purpose of the project was to study precipitation behavior and structure stability in six advanced heat resistant alloys. Each sample were subjected to a creep rupture test in 600 or 700°C depending on the alloy type. Two parts of each alloy where examined; one part which had been affected by creep and another part which was unaffected by creep. A literature study was performed first to gain knowledge of the scientific theory utilized in this project, namely creep, precipitation hardening, and about the different materials which were analyzed. Preliminary results for the phase composition of the materials were obtained from a Thermo-Calc (TC) simulation. The SEM-images showed nothing noteworthy for any sample due to the roughness of the sample surfaces. The EDS-analysis showed chromium depletion in the centers of the aged samples of HT9 and Sanicro® 75X. Other minority phases such as Cr23C6 in Sanicro®70, P-phase and a titanium nitride phase in sanicro® 60X, VB in Esshete 1250 and Sigma-phase in 4C54 were identified using EDSmapping. It was found that when using XRD to analyze the phase compositions of small samples it is impractical to have the samples cast in bakelite beforehand. The XRD-results obtained in this project showed that more than 90% of the XRD diffractogram for every sample was graphite, which made the identification of minority phases impossible. The quality of the LOM-images varied greatly between samples, for 4C54 grain sizes were measured in all images, for Esshete 1250 grain sizes were measured for the crept sample, and for Sanicro® 60X measurements could only be taken from one image. Most of the sample preparation was insufficient to achieve the test results necessary for complete microstructural analysis and phase analysis of the samples. The mistakes in the practical steps of the project were noted and improvements for these mistakes are presented in the conclusion.

The demand for metals is great for the purpose of developing green technologies, and EU has listed 30 metals and minerals that are of critical importance for the maintenance and evolving of today’s society, so called critical materials. However, mining of raw materials generates mine waste which can have adverse effect on human health, ecosystems, and surrounding areas. To be able to prevent the release of toxic levels of elements from mine waste, an understanding of how different elements behave in the secondary environments is necessary in order to use the most successful methods for mining remediation. It is common that secondary minerals, such as gypsum and/or HFOs (hydrous ferric oxides), forms in mine waste or in downstream environments, depending on the geochemical conditions. From prior studies, it is well established that trace elements are sorbed by HFO. But studies are scares regarding co-precipitation of elements with secondary gypsum formation, and few studies investigates the possibility of critical elements to be captured by secondary minerals. In this study, a prior unknown white precipitation along with tailings material from the Smaltjärnen tailings beach in Yxsjöberg, Sweden, has been investigated by combining mineralogical studies (SEM-EDS and DXRD analysis) with sequential extraction. The aim with the study was to identify the precipitation and to examine if critical elements had co-precipitated with the precipitation and HFOs within the sample. From the results it was possible to prove that the white precipitation was gypsum (CaSO4*2H2O), and it was indicated that some of the critical elements (beryllium for instance) showed affinity for gypsum, and that bismuth, tungsten, and chromium were sorped by HFOs. The combining of chemical analysis with mineralogical studies was of great importance for determining in which mineral phases the leached elements were situated, and the study has shown that secondary gypsum formation can be an important sink for some critical elements. More studies should be performed within this field of research to further investigate the importance of secondary minerals for scavenging of elements, not only to prevent toxic levels to be leached, but also to capture these elements in the purpose of re-mining. / Idag är behovet av metaller stort inom användningsområden för att utveckla gröna teknologier. EU har därför listat 30 metaller och mineral (kritiska material) som anses vara kritiska för att underhålla och utveckla dagens samhälle. Men brytning av råmaterial resulterar i generering av gruvavfall där avfallet potentiellt kan utgöra en risk för att skada bland annat människors hälsa och ekosystem. För att kunna förhindra att giftiga halter av grundämnen släpps ut från gruvavfall så krävs en förståelse om hur olika ämnen beter sig i sekundära miljöer, för att på så sätt kunna tillämpa de mest framgångsrika metoderna för sanering och återställning av gruvområden. Det är vanligt förekommande att sekundära mineraler (såsom gips och järnhydroxider) fälls ut i gruvavfallet och/eller nedströms om gruvområdet beroende på de geokemiska förhållandena. Tidigare studier har visat att spårämnen kan binda till järnhydroxider, men endast ett fåtal studier undersöker samutfällning av olika spårämnen tillsammans med sekundärt gips. Hur specifikt kritiska metaller kan fångas upp av sekundära mineral är ännu inte välstuderat. I denna studie har en vit, tidigare okänd, utfällning provtagits från en av deponierna med anrikningssand i den historiska volframgruvan i Yxsjöberg. Utfällningen identifierades genom att kombinera mineralogiska studier (SEM-EDS och DXRD analys) med kemiska lakvattenanalyser från en sekventiell lakning. Målet med studien var att mineralogiskt karaktärisera den okända utfällningen och att undersöka om kritiska ämnen möjligen samutfällts tillsammans med de sekundära mineralen. Studien visade att utfällningen var sekundärt gips (CaSO4*2H2O) och det kunde påvisas att vissa kritiska metaller visade affinitet för gipset (exempelvis beryllium) och att andra kritiska metaller samutfällts/adsorberats av järnhydroxider. Att kombinera dom olika metoderna visade sig att vara till stor nytta för att kunna påvisa vilka mineral dom olika grundämnena var bundna till, och studien har även visat att sekundärt gips kan vara en sänka för vissa kritiska metaller. Mer studier bör utföras inom detta forskningsområde i framtiden för att vidare undersöka hur sekundära mineral kan binda kritiska metaller, inte endast för att förhindra att giftiga halter av metaller släpps ut, utan också för att undersöka möjligheten att återvinna gruvavfallet för utvinning av kritiska metaller.

Made available in DSpace on 2017-07-25T19:29:44Z (GMT). No. of bitstreams: 1 Clever Briedis.pdf: 1258130 bytes, checksum: ffdbaa47bb93b2258b4ff51d6b50f9ad (MD5) Previous issue date: 2010-06-14 / Liming is the most often practice used to neutralize soil acidity, and also promotes chemical changes that can alter the soil organic matter (SOM) pools and the mechanisms of flocculation, formation and stabilization of macro-and microaggregates. The objective of this study was to evaluate carbon sequestration, in the whole and in the aggregates samples, and the changes in the SOM pools affected by liming in a long-term no-tillage. The experiment was conducted in an Oxisol, located in Ponta Grossa, PR. The experimental design was a randomized complete block, arranged as split plot with three replications. The main plot consisted of dolomite lime applied on the soil surface at a 0 or 6 Mg ha-1 in 1993, and 0 or 3 Mg ha-1 in 2000 in plots previously with and without lime, and the treatments was assigned as: 0+0, 6+0, 0+3 and 6+3 Mg ha-1. The subplots were represented by sampling depth and consist of 0-2.5, 2.5-5, 5-10 and 10-20 cm layer. The soil samples were taken in September 2008 and the total organic carbon (TOC) was analyzed in the whole sample, in the aggregates and in the particulate organic carbon (POC) and in the fraction associated with minerals carbon (OCAM). Aggregates of 8-19 mm, in the 0-2.5 cm layer were analyzed by using scan microscope spectrometer X-ray (EDS) for elemental analysis of carbon (C) and calcium (Ca). Liming promoted accumulation of TOC mainly in the layer 0-2.5 cm. The TOC stocks at 0-20 cm were 49.9, 52.9, 52.7 and 57.5 Mg ha-1 for 0+0, 6+0, 0+3, 6 +3 treatments, respectively. Stocks in the SOM fractions were also increased with liming. The increase in POC stock was close relationship (R2 = 0.98, P = 0.011) with the C accumulated input through crop residue, which was higher in plots that were limed. A positive correlation was found between TOC and C extracted in hot water (CHW), total polysaccharides (TP) and labile (LP). Correlations also showed that TOC had a closer relationship with POC than with OCAM, suggesting a greater influence on the labile fraction of TOC increase with liming. In aggregate, the effect of liming in TOC accumulation was mainly in 0-2.5 cm depth. The treatments with liming showed high mean weight diameter (MWD), which provided a large stock of TOC in the 8-19 mm aggregate size. A higest proportion of large aggregates with liming was closely correlated with the TOC content of whole sample. The highest liming dosis resulted in both COP and in OCAM, in the largest class of aggregates. The proportion of POC average of the treatments in relation to OCAM, this class of aggregates, has decreased in depth, and were 18, 13, 10 and 8% at depths of 0-2.5, 2.5-5, 50-10 and 10-20, respectively. Elemental analysis of C and Ca showed a positive correlation of those elements contained in a section of clay from the center of 8-19 mm aggregates. The results suggest that application of lime in soil with clay fraction dominated by kaolinite, brings benefits to structuring and promotes an increase of C in the whole sample and in aggregates. / A calagem é a prática mais utilizada para neutralizar a acidez do solo, porém promove também modificações químicas capazes de alterar os compartimentos da matéria orgânica do solo (MOS) e mecanismos de floculação, formação e estabilização de macro e microagregados. O objetivo desse trabalho foi avaliar o seqüestro de carbono, na amostra integral e nos agregados, e as alterações nos compartimentos da MOS afetados por calagem superficial em sistema plantio direto de longa duração. O experimento foi conduzido em um Latossolo Vermelho textura média, no município de Ponta Grossa, PR. O delineamento experimental foi o de blocos completos ao acaso em parcelas subdivididas, com três repetições. As parcelas consistiram da aplicação de calcário dolomítico na superfície do solo na dose de 0 ou 6 Mg ha-1 em 1993, e dose de 0 ou 3 Mg ha-1 em 2000 nas parcelas previamente com e sem calcário, compondo os tratamentos: 0+0; 6+0; 0+3 e 6+3 Mg ha-1. As subparcelas foram constituídas pelas profundidades de coleta, sendo realizadas em 0-2,5, 2,5-5, 5-10 e 10-20 cm de profundidade. As coletas de solo foram realizadas em setembro de 2008 e analisados os conteúdos de carbono orgânico total (COT) na amostra total, nos agregados e nas frações particulada (COP) e associada aos minerais (COAM) da matéria orgânica do solo (MOS). Agregados de 8-19 mm, da camada 0-2,5 cm, foram analisados através do uso de espectrômetro de dispersão de raios X (EDS) para a análise elementar de carbono (C) e cálcio (Ca). A calagem promoveu acúmulo de COT, principalmente na camada 0-2,5 cm. Os estoques de COT na camada de 0-20 cm foram 49,9, 52,9, 52,7 e 57,5 Mg ha-1 para os tratamentos 0+0, 6+0, 0+3 e 6+3, respectivamente. Os estoques nas frações da MOS também foram aumentados com a calagem. O aumento no estoque de COP foi estreitamente relacionado (R2=0,98; P=0,011) com a adição acumulada de C via resíduo cultural, a qual foi mais elevada nas parcelas que receberam calagem. Houve correlação positiva entre COT e carbono em água quente (CAQ), polissacarídeos totais (PT) e lábeis (PL). Correlações também demonstraram que o COT teve relação mais estreita com o COP do que com COAM, sugerindo maior influência da fração lábil no aumento de COT com a calagem. Nos agregados, a calagem proporcionou acúmulo de COT principalmente na profundidade de 0-2,5 cm. A calagem aumentou o diâmetro médio ponderado (DMP), proporcionando grande estoque de COT na classe de agregado 8-19 mm. A elevada proporção de agregados grandes nos tratamentos com calagem foi estreitamente correlacionado com o conteúdo de COT da amostra integral. A maior dose de calcário proporcionou aumento no estoque de COT tanto em COP quanto em COAM, visto principalmente na maior classe de agregados. A proporção de COP em relação ao COAM, na média dos tratamentos, nessa classe de agregados, diminuiu em profundidade, ficando em torno de 18, 13, 10 e 8 % nas profundidades de 0-2,5, 2,5-5, 5-10 e 10-20, respectivamente. Análise elementar de C e Ca demonstraram correlação positiva dos dois elementos contidos em uma secção da fração argila do centro de agregados de 8-19 mm. A aplicação de calcário, em solo dominado na fração argila por caulinita, traz benefícios à estruturação e promove aumento de C na amostra integral e nos agregados.

Les artefacts en céramique ont une longue histoire et ont été récupérés dans presque toutes les régions du monde. La conservation n’est que rarement impactée par le milieu d’enfouissement. Donc, ils sont des matériaux idéaux pour comprendre l'histoire et la culture de homme. Les principales études archéologiques sur les céramiques anciennes concernent la provenance (datation, atelier, commerce), les matières premières (identification, origine), le processus de fabrication et l'utilisation (analyse des résidus de contenu). Mon travail porte plus précisément sur le processus de fabrication. Les principales étapes du processus de fabrication sont: la sélection des matières premières, la préparation, le façonnage, salle de bains, sur deux possibilités. Soit le vase est cuit avant l'étape de décoration, soit la décoration est appliquée sur le vase cru. Pour finir, l'ensemble est cuit. Mon objectif est d'obtenir des informations sur le procédé de fabrication en analysant la structure des céramiques anciennes, et en particulier, la structure des couches décoratives. La structure des céramiques anciennes est une structure complexe en couches avec des hétérogénéités à différentes échelles (mm à nm). Une céramique décorée est généralement composée d'une pâte et d'un revêtement, y compris de la décoration. Le revêtement peut contenir des natures différentes. L'épaisseur peut être variable de mm à nm. La couche décorative peut être une partie ou du tout la revêtement. La couche décorative peut être constitutive d'une phase vitrifiée amorphe et divers cristaux, tels que cristaux colorants, feldspath, quartz, etc., dont la taille varie de plusieurs microns à nanomètre. La description de cette structure nécessite l'analyse à haute résolution (nm) avec grande zone représentative (souvent plusieurs mm3). C’est difficile à réaliser. Dans mon travail, j'ai proposé une autre approche. L'approche est basée sur trois étapes. Premièrement, les analyses rapides (principalement microscopie optique) à faibles résolutions sont effectuées pour analyser et sélectionner la zone nécessitant une analyse à haute résolution. Ensuite, la zone sélectionnée est analysée à haute résolution par des techniques appropriées en tenant compte des informations recherchées. Troisièmement, on essaie de construire la structure de l'objet sur la base des données partielles, et d’en déduire le processus de fabrication. Je vais illustrer cette approche par trois exemples. La première concerne le pigment jaune de la terre sigillée marbrée romaine (chapitre III). Le second concerne le processus de cuisson des poteries attiques (chapitre III). Le troisième concerne les variations de couleur de la décoration bleue des porcelaines Qinghua (chapitre IV). / Ceramic artifacts have a long history and have been discovered worldwide. Their conservations are rarely impacted by the burial sites. Thus, they are ideal materials for understanding the human history and culture. The main archaeological studies concerning ancient ceramics contains provenance (dating, workshop, trade), raw materials (identification, origin), manufacturing process and utilization (analysis of content residues). For my work, I focused on the investigation of the manufacturing process. The main steps of fabrication process of ancient ceramics is composed of selection of raw materials, preparation (leaching, purification, body, glaze or slip, pigments), shaping (the plastic paste is shaped to the lathe or using the molds). Then, there are two possibilities: either the vase is fired before the decoration stage, or the decoration is applied to the raw vase. To finish, the whole is fired. My objective is to obtain information on the manufacturing process by analyzing the structure of ancient ceramics, and in particular the structure of decorative layers. The structure of ancient ceramics is complex with heterogeneities at different scales (mm to nm). A decorated ceramic generally is composed of a body and a coating, which including of the decoration. The coating could contain different natures. The thickness can be variable from mm to nm. The decorative layer can be a part of the coating or the whole coating. The decorative layer can be constituent of an amorphous vitrified phase and diverse crystals, such as colorant crystals, feldspar, quartz, etc., of which the size varies from several microns to nanometer. The description of such structure requires the analysis at high resolution (nm) with large representative zone (often, several mm3). It is difficult to realize. In my work, I proposed an alternative approach. The approach is based on three stages. Firstly, the rapid investigations (principally, optical microscopy) at low resolutions are effected to analyze and select the zone requiring analysis at high resolution. Secondly, the selected zone is analyzed at high resolution by appropriate techniques according to the information sought. Thirdly, I try to construct the structure of the object based on the partially data, and therefore deduce the manufacturing process. I will illustrate this approach through three examples. The first one concerns the yellow pigment of the Roman marbled terra sigillata (Chapter III). The second one is about the firing process of Attic potteries (Chapter III). The third one concerns the color variations of blue decoration of Qinghua porcelains (Chapter IV).

Les amibes à thèque, également appelés thécamoebiens, sont des micro-organismes unicellulaires, qui construisent une enveloppe rigide, appelée thèque (Adl et al., 2012). Ces thèques ont des tailles, formes et natures très variées (Ogden & Hedley, 1980). Les récentes études sur la composition des thèques ont conduit à émettre l’hypothèse que les amibes xénosomiques (constituées de particules exogènes), peuvent constituer des bio-indicateurs pertinents de la diversité particulaire de l’environnement minéral, organique et biologique dans lequel elles évoluent.L’objectif principal des recherches menées au cours de cette thèse vise donc à caractériser la composition des thèques d’amibes xénosomiques et à en évaluer leur utilisation potentielle en tant que bio-indicateurs des dépôts de particules d'origine atmosphérique. Pour cela, des thèques d’amibes ont été analysées in situ en conditions naturelles et après dépôts artificiels de particules minérales allochtones.Ces travaux permettent de dégager plusieurs conclusions majeures :(1) La taille des particules minérales intégrées dans la thèque xénosomique de Bullinularia indica est similaire à celle des particules minérales transportées dans l'atmosphère; (2) les particules minérales intégrées dans les thèques sont des silicates stables dans les conditions physico-chimiques régnant dans les tourbières, les bryophytes et les sols étudiés; (3) certains minéraux comme la phlogopite, même lorsqu’ils sont présents en de fortes concentrations, ne sont jamais intégrés par les amibes; (4) la combinaison des observations portant sur la taille, la forme et la nature des particules utilisées par des amibes xénosomiques permet de poser les bases de l'utilisation des amibes à thèques pour la bio-indication de la diversité particulaire atmosphérique récente ou ancienne. / Theca-like amoebae, also called thecaamoebius, are unicellular microorganisms, which construct a rigid envelope called theca (Adl et al., 2012). These themes have very varied sizes, shapes and natures (Ogden & Hedley, 1980). Recent studies on the composition of the themes have led to the hypothesis that xenosomal amoebae (constituted by exogenous particles) can constitute relevant bio-indicators of the particulate diversity of the mineral, organic and biological environment in which they evolve . The main objective of the research carried out during this thesis is therefore to characterize the composition of the xenosomal amoebae and to evaluate their potential use as bioindicators of deposits of atmospheric particles. For this purpose, amoeba theae were analyzed in situ under natural conditions and after artificial deposits of allochtonous mineral particles. Several major conclusions can be drawn from this work: (1) The size of the mineral particles integrated in the xenosomal theca of Bullinularia indica Is similar to that of mineral particles transported into the atmosphere; (2) the mineral particles integrated into the thecs are stable silicates under the physico-chemical conditions prevailing in the peatlands, bryophytes and soils studied; (3) some minerals such as phlogopite, even when present in high concentrations, are never integrated by amoebae; (4) the combination of observations on the size, shape and nature of the particles used by xenosomic amoebae forms the basis for the use of tea amoeba for bioindication of recent or former atmospheric particulate diversity .

Resumen (Castellano) El aumento del consumo de energía global junto con las preocupaciones ambientales ha generado mucho interés por las fuentes de energía alternativas y limpias, como la energía solar fotovoltaica. Los investigadores en la comunidad fotovoltaica han estado buscando formas de reducir costos mientras mantienen o aumentan las eficiencias. Una mejor comprensión de los materiales implicados es esencial para el rápido desarrollo de nuevas tecnologías. Las películas delgadas I-III-VI2 ofrecen sistemas prometedores para lograr células solares de alta eficiencia a un costo menor. De hecho, al adaptar la composición de los compuestos, es posible cambiar la banda prohibida del material para captar la luz solar de manera más eficiente. Esta tesis se centra en la preparación y caracterización del material de la capa absorbente, especialmente las películas delgadas nanocristalinas y la consideración de las características estructurales y eléctricas de dicha capa principal absorbente de células. La tesis examina cómo las diferentes técnicas de preparación y uso del material podrían afectar las propiedades del películas delgadas sintetizadas. Películas delgadas CuInSe2 y CuInS2 se depositaron sobre sustratos de vidrio ITO usando la técnica de electrodeposición en solución acuosa. Las películas electrodepositadas se caracterizaron por difracción de rayos X (XRD), microscopía electrónica de barrido (SEM) y análisis de rayos X de energía dispersiva (EDS). Se investigaron los efectos de recocido sobre los precursores electrodepositados. La estructura de calcopirita de CuInSe2/CuInS2 mostró una mejora de la cristalinidad después del tratamiento posterior de selenización/sulfurización en atmósfera Se/S, respectivamente. Los estudios de XRD y SEM revelaron una mejora de la calidad cristalina de las películas de CIS después de los tratamientos térmicos. Las propiedades ópticas de las películas delgadas recocidas CuInSe2-Se y CuInSe2-S se han estudiado para determinar el efecto del proceso de recocido en diferentes ambientes de selenio y azufre. Además, modificamos el CuInxCryGa1-x-ySe2 de cobre indio, donde x = 0.4, y = (0.0, 0.1, 0.2, 0.3) la capa de superestrato por el proceso de recubrimiento por centrifugado. CuInxCryGa1-xySe2 donde x = 0.4, y = (0.0, 0.1, 0.2, 0.3) nanopartículas han sido sintetizadas en primer lugar usando un método hidrotermal químico húmedo que se basa en un proceso térmico sin vacío sin ningún proceso de selenización adicional. Introduciendo diferentes fuentes de metal en un autoclave con etilenamina como solvente, se obtuvieron nanopartículas de CIGS a diferentes temperaturas en un rango de 190-230 °C. Los resultados de la difracción de rayos X (XRD) confirmaron la formación de una estructura de calcopirita CuInxCryGa1-x-ySe2 tetragonal. Finalmente, se estudió el efecto de la temperatura de recocido en los materiales tipo Kesterita (como el Cu2ZnSnS4) que son materiales de muy bajo costo y que no dañan el medio ambiente. Estudiamos el crecimiento de las películas delgadas cuaternarias Cu2ZnSnS4 (CZTS) de kesterita mediante un depósito electroquímico de un solo paso seguido de un recocido a baja temperatura. La influencia de diferentes atmósferas de recocido a tiempos de recocido constantes (t = 45 min) y parámetros de control de preparación fijos; es decir, concentración de la solución de materiales de partida (sales de metales precursores), tiempo de deposición y potencial de electrodeposición. Se estudiaron las propiedades estructurales, de composición, morfológicas y ópticas, así como las propiedades fotoelectroquímicas. / Abstract Increasing global energy consumption together with environmental concerns has led to much interest in alternative, cleaner sources of energy such as solar photovoltaic. Researchers in the solar cell community have been looking for ways to reduce costs while maintaining or increasing already high efficiencies. A fundamental understanding of the materials under consideration is essential to rapid development of new technologies. The I-III-VI2 thin films offer promising systems for achieving high efficiency solar cells at lower costs. In fact, by tailoring the chemistry of the compounds it is possible to change the bandgap of the material in order to collect sunlight more efficiently. First of all, this thesis focuses on absorber layer material preparation and characterization, especially nanocrystalline thin films and consideration of both structural and electrical characteristics of such main cell absorber layer.The thesis examines how different preparation techniques and material usage could affect the properties of the synthesized thin films (absorber layer). In this study CuInSe2 and CuInS2 thin films were deposited onto ITO glass substrate using the electrodeposition technique in aqueous solution. The electrodeposited films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDS). The annealing effects on the electrodeposited precursors were investigated. The chalcopyrite structure of CuInSe2/CuInS2 showed an enhancement of crystallinity after subsequent selenization/sulfurization treatment in Se/S atmosphere, respectively. XRD and SEM studies revealed a dramatic improvement of the crystalline quality of CIS films after annealing treatments. The optical properties of annealed CuInSe2-Se and CuInSe2-S thin films have been studied in order to determine the effect of annealing process in different selenium and sulfur atmosphere. In the second step we modified copper indium CuInxCryGa1-x-ySe2 where x=0.4, y= (0.0, 0.1, 0.2, 0.3)superstrate layer by spin coating process. CuInxCryGa1-x-ySe2 where x=0.4, y= (0.0, 0.1, 0.2, 0.3) nanoparticles have been synthesized firstly using a wet chemical hydrothermal method that is based on a non-vacuum thermal process without any additional selenization process. Introducing different metal sources in an autoclave with ethylenediamine as solvent, CIGS nanoparticles were obtained at different temperatures range 190-230°C. The X-ray diffraction (XRD) results confirmed the formation of a tetragonal CuInxCryGa1-x-ySe2 chalcopyrite structure. Finally, we turned again to the study of the annealing temperature effect onKesterite materials but this time in those of very low-cost materials and environmentally friendly Cu2ZnSnS4. We studied the growth of quaternary Cu2ZnSnS4 (CZTS) kesterite thin films by a single step electrochemical deposition followed by annealing at low temperature. The influence of different annealing atmospheres at constant annealing times (t = 45 min) and fixed preparation controlling parameters; i.e., starting materials (precursor metal salts) solution concentration, time of deposition and electrodeposition potential. Structural, compositional, morphological, and optical properties, as well as photoelectrochemical properties were studied. / Resum (Valencià) L'augment del consum d'energia global juntament amb les preocupacions ambientals ha generat molt d'interès per les fonts d'energia alternatives i netes, com ara l'energia solar fotovoltaica. Els investigadors de la comunitat fotovoltaica han estat buscant formes de reduir costos mentre mantenen o augmenten les eficiències. Una millor comprensió dels materials implicats és essencial per al ràpid desenvolupament de noves tecnologies. Les pel·lícules primes I-III-VI2 ofereixen sistemes prometedors per aconseguir cèl·lules solars d'alta eficiència a un cost menor. De fet, en adaptar la composició dels compostos, és possible canviar la banda prohibida del material per captar la llum solar de manera més eficient. Aquesta tesi se centra en la preparació i caracterització del material de la capa absorbent, especialment les pel·lícules primes nanocristal·lines i la consideració de les característiques estructurals i elèctriques d'aquesta capa principal absorbent de cèl·lules. La tesi examina com les diferents tècniques de preparació i ús del material podrien afectar les propietats del pel·lícules primes sintetitzades. Pel·lícules primes CuInSe2 i CuInS2 es van dipositar sobre substrats de vidre ITO usant la tècnica d'electrodeposició en solució aquosa. Les pel·lícules electrodepositadas es van caracteritzar per difracció de raigs X (XRD), microscòpia electrònica de rastreig (SEM) i anàlisi de raigs X d'energia dispersiva (EDS). Es van investigar els efectes de recuit sobre els precursors electrodepositados. L'estructura de calcopirita de CuInSe2/CuInS2 va mostrar una millora de la cristal·linitat després del tractament posterior de selenització/sulfurització en atmosfera de Se o S, respectivament. Els estudis de XRD i SEM van revelar una millora de la qualitat cristal·lina de les pel·lícules de CIS després dels tractaments tèrmics. Les propietats òptiques de les pel·lícules primes recuites CuInSe2-Es i CuInSe2-S s'han estudiat per determinar l'efecte del procés de recuit en diferents ambients de seleni i sofre. A més, modifiquem el CuInxCryGa1-x-ySe2 de coure indi, on x = 0.4, i = (0.0, 0.1, 0.2, 0.3) la capa d'superstrat pel procés de recobriment per centrifugat. CuInxCryGa1-x-ySe2 on x = 0.4, i = (0.0, 0.1, 0.2, 0.3) nanopartícules han estat sintetitzades en primer lloc fent servir un mètode hidrotermal químic humit que es basa en un procés tèrmic sense buit sense cap procés de selenización addicional. Introduint diferents fonts de metall en un autoclau amb etilenamina com solvent, es van obtenir nanopartícules de CIGS a diferents temperatures en un rang de 190- 230 °C. Els resultats de la difracció de raigs X (XRD) van confirmar la formació d'una estructura de calcopirita CuInxCryGa1-x-ySe2 tetragonal. Finalment, es va estudiar l'efecte de la temperatura de recuit en els materials tipus kesterita (com el Cu2ZnSnS4) que són materials de molt baix cost i que no danyen el medi ambient. Vam estudiar el creixement de les pel·lícules primes quaternàries Cu2ZnSnS4 (CZTS) de kesterita mitjançant un dipòsit electroquímic d'un sol pas seguit d'un recuit a baixa temperatura. La influència de diferents atmosferes de recuit a temps de recuit constants (t = 45 min) i paràmetres de control de preparació fixos; és a dir, concentració de la solució de materials de partida (sals de metalls precursors), temps de deposició i potencial d'electrodeposició. Es van estudiar les propietats estructurals, de composició, morfològiques i òptiques, així com les propietats fotoelectroquímiques / Kamal Abdelhamied Saber, S. (2018). Synthesis and characterization of some nano-selenides and their applications in solar cells [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/107389 / TESIS

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Effects of sodium sulfate (Na2SO4) particle deposition on the atmospheric corrosion of copper (Cu) metal and a Cu-based alloy (Cu5Al5Zn) used in architectural applications were investigated at laboratory conditions compared with effects induced by sodium chloride (NaCl) and to some extent ammonium sulfate (NH4)2SO4 induced corrosion. Pre-deposited surfaces were exposed to repeated wet/dry conditions in a climatic chamber and the formation of corrosion products were assessed using light optical microscopy (LOM), scanning electron microscopy with elemental analysis (SEM/EDS), Fourier transform infrared techniques (FTIR microscopy) and cathodic reduction (CR). Na2SO4 induced corrosion resulted in corrosion cells locally over the surface on both Cu and Cu5Al5Zn, of increased oxygen content in the anodic area of the cells (center of pre-deposited area). The main corrosion products formed on Cu metal are basic copper sulfates and cuprite (Cu2O), while basic sulfates (copper and/or zinc) and Cu2O were the main corrosion products formed on Cu5Al5Zn. A combined deposition of Na2SO4 + NaCl was carried out on the Cu5Al5Zn alloy using two different deposition methods to investigate the possible interplay from a corrosion initiation perspective between the two salt particles. For short time exposed Cu5Al5Zn (1 cycle), two different corrosion cells formed, mainly induced by Na2SO4 and NaCl. Corrosion products formed in anodic areas of a Na2SO4 induced corrosion cell were similar to findings observed for Cu5Al5Zn pre-deposited with Na2SO4 only, whereas peripheral cathodic areas primarily were affected by NaCl dissolution and predominantly composed of Cu2O that was the main corrosion product with small amount of hydroxides and carbonates of the NaCl induced corrosion cells. After relatively longer exposure periods (2 and 6 wet/dry cycles), NaCl dominated the corrosion of the entire surface with the formation of more Cu2O, hydroxides and carbonates. Cathodic reduction findings revealed a negative interplay on corrosion for the mixed salt after short time exposures (1 and 2 cycles), whereas a slight synergistic effect was evident after a longer exposure period (6 cycles), compared with corrosion induced by single salts.

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