Composite films combining electrospun fiber network and epitaxial oxide by chemical solution deposition

We report the preparation of a novel type of composites films by chemical solution deposition. It consists of an epitaxial oxide on a single crystal template inside which an oxide fiber network is dispersed. Electrospinning is used for the deposition of the fiber network whereas the continuous epitaxial phase is spin-coated. Good coating is observed between the liquid precursor of the continuous oxide and the fibers and remarkably, epitaxial (001) growth of the YBa2Cu3O7-x is not affected by the presence of the fiber network because both oxides do not react to each other. Topological continuity of the continuous phase is probed by electrical conductivity measurements, rendering nearly the same values reported for fiber-free films. Mechanical properties are determined by nanoindentation at low penetration depths to avoid the effect of the single crystal beneath the composite. Enhanced mechanical properties are found (hardness, Young's modulus, elastic recovery and wear resistance)

Chemical Solution Deposition of Insulating Yttria Nanolayers as Current Flow Diverter in Superconducting GdBa2Cu3O7-δ Coated Conductors

The primary benefit of a metallic stabilization/shunt in high temperature superconductor (HTS) coated conductors (CCs) is to prevent joule heating damage by providing an alternative path for the current flow during the HTS normal state transition (i.e., quench). However, the shunt presence in combination with unavoidable fluctuations in the critical current (I c) of the HTS film can develop a localized quench along the CC's length if the operational current is kept close to I c. This scenario, also known as the hot-spot regime, can lead to the rupture of the CC if the local quench does not propagate fast enough. The current flow diverter (CFD) is the CC architecture concept that has proven to increase the conductor's robustness against a hot-spot regime by simply boosting the quench velocity in the CC, which avoids the shunt compromise in some applications. This work investigates a practical manufacturing route for incorporating the CFD architecture in a reel-to-reel system via the preparation of yttrium oxide (Y2O3) as an insulating thin nanolayer (∼100 nm) on top of a GdBa2Cu3O7 (GdBCO) superconductor. Chemical solution deposition (CSD) using ink jet printing (IJP) is shown to be a suitable manufacturing approach. Two sequences of the experimental steps have been investigated, where oxygenation of the GdBCO layer is performed after or before the solution deposition and the Y2O3 nanolayer thermal treatment formation step. A correlated analysis of the microstructure, in situ oxygenation kinetics, and superconducting properties of the Ag/Y2O3/GdBCO trilayer processed under different conditions shows that a new customized functional CC can be prepared. The successful achievement of the CFD effect in the case of the preoxygenated customized CC was confirmed by measuring the current transfer length, thus demonstrating the effectiveness of the CSD-IJP as a processing method.We acknowledge the funding of this research by FASTGRID Project (EU-H2020, 721019); the Projects COACHSUPENERGY (MAT2014-51778-C2-1-R) and SUMATE (RTI2018-095853-BC21 and RTI2018-095853-B-C22) from the Spanish Ministry of Economy and Competitiveness, which were cofunded by the European Regional Development Fund; and the Project 2017-SGR 753 from Generalitat de Catalunya and the COST Action NANOCOHYBRI (CA16218). ICMAB authors also acknowledge the Center of Excellence awards Severo Ochoa SEV-2015-0496 and CEX2019-000917-SWith funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000917-S).Peer reviewe

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

Growth and characterization of chemical solution based nanostructured coated conductors with CeO(2) cap layers

100 años después de que el físico holandés Heike Kamerlingh Onnes descubriera que el mercurio tiene una resistencia eléctrica igual a cero, cuando se enfría en el helio líquido, los superconductores son lanzados finalmente para su uso en las redes eléctricas. Los cables superconductores pueden transportar diez veces más energía que el mismo volumen de los cables convencionales de cobre. Aunque parte de esta energía se pierde (pérdidas de corriente alterna) y se necesita usar el nitrógeno líquido para enfriar los cables superconductores y otros dispositivos, tales sistemas de energía son mucho más eficientes que las basadas en cableado de cobre, donde las pérdidas de potencia, alrededor de 7-10%, son en forma de calor. Debido a esto, países como EE.UU., Japón, Corea del Sur, China y Europa han establecido objetivos para las redes "verdes" de electricidad, reduciendo la generación de gases de efecto invernadero (CO2) y construyendo "redes inteligentes" basadas en superconductores más eficientes y robustos. Los cables superconductores de alta temperatura están hechos de un óxido de itrio, bario, cobre (YBCO) que forma parte de la familia de las cerámicas superconductoras de “alta temperatura”, descubiertas por primera vez en 1986. Las perspectivas atractivas ofrecidas por los conductores recubiertos (Coated Conductors), conocidos como la 2 ª generación de superconductores de alta temperatura (2G-HTS), han dado lugar a amplios y fructíferos esfuerzos de investigación y desarrollo para que estos sean preparados para el mercado [2]. Recientemente, LS Cable, una compañía de Corea del Sur con sede en Anyang-si, cerca de Seúl, ha ordenado tres millones de metros de cable superconductor de la firma American Superconductor desde EE.UU., en Devens, Massachusetts, que es el más alto pedido comercial de HTS CC hasta el momento [1] . Los superconductores de alta temperatura (HTS) tienen un enorme potencial para mejorar significativamente los sistemas de energía existentes, tales como cables, motores, transformadores, imanes y generadores, debido a que se puede alcanzar una mayor densidad de energía y se pueden reducir las pérdidas, comparado con los cables de cobre o cables superconductores de baja temperatura [3]. Los materiales superconductores abren tecnologías completamente nuevas en el sector de la energía, tales como limitadores de corriente o de levitación magnética inherentemente estable. Como ejemplos de aplicaciones innovadoras, deben ser mencionados sistemas avanzados de energía para barcos "all-electrical", molinos de viento en la costa y sistemas de transporte. Aunque la investigación sobre materiales HTS ha tenido mucho éxito en el pasado, el desarrollo de materiales superconductores de bajo coste sigue siendo un factor clave de éxito y, a fin de traer estos materiales emergentes en el mercado en un plazo razonable, requiere una investigación de materiales mucho más básica y aplicada. El objetivo principal de esta tesis, es el desarrollo de nuevas arquitecturas simplificadas nanoestructuradas de Coated Conductors, basadas en la deposición de soluciones químicas (CSD). Para ello, el crecimiento y la caracterización de estos Coated Conductors, se ha investigado primero sobre monocristales de YSZ, donde el CeO2 se puede crecer fácilmente como tapa tampón. El conocimiento generado puede ser útil para dos tipos de sustratos metálicos: 1.- sustratos Ni5%W RABiTS con MODLZO como capa tampón; 2.- sustratos policristalinos de Stainless Steel (SS) con ABADYSZ como capa tampón. Teniendo en cuenta la calidad de los sustratos metálicos existentes, esta tesis se ha concentrado en los sustratos policristalinos de Stainless Steel (SS), enviados por la empresa alemana Bruker HTS. El primer paso para obtener arquitecturas simplificadas fue la investigación del oxido de cerio dopado con Gd y Zr que mejor se adapta a los sustratos mencionados. El segundo paso consistió en crecer películas delgadas superconductoras de YBa2Cu3O7-x, con la ruta de los trifluoracetatos. Este trabajo comienza con una breve descripción de la superconductividad, seguido por una breve introducción sobre el compuesto superconductor YBCO y termina con los principales métodos para la obtención de películas de YBCO texturadas de alta calidad. Una caracterización completa de las muestras con diversas técnicas (Microscopía de fuerza atómica (AFM), Difracción de rayos X (DRX), Microscopía Electrónica de Barrido (SEM), Microscopía Electrónica de Transmisión (TEM), Difracción de electrones rasantes (RHEED), Deposición con láser pulsado (PLD), SQUID, Reflectividad de rayos X (XRR) y medidas eléctricas de transporte) es necesaria para comprender el mecanismo complejo de cada superconductor y las interacciones entre las diferentes capas. Han sido investigadas varias películas de óxido de cerio dopado usado como capa tampón superior, preparadas por spin coating. Los requisitos técnicos para obtener Coated Conductors de alta calidad son muy diversos. Para lograr una epitaxia de alta calidad y alta Jc, es necesario llevar a cabo una detallada caracterización morfológica y estructural por medio de SEM y DRX. La microestructura de la capa de YBCO debe estar estrechamente correlacionada con la de la capa tampón. Para estudiar más en detalle las propiedades superconductoras, se han realizado medidas inductivas y de transporte para examinar el flujo de corriente en las películas de YBCO depositadas sobre distintos sustratos. Los resultados obtenidos con las capas de CeO2 crecidas sobre ABADYSZ/SS han sido reportados. La última parte de esta tesis está dedicada al desarrollo de películas delgadas de materiales nanocompuestos de MODBaZrO3-YBa2Cu3O7-x y MODBaCeO3-YBa2Cu3O7-x usando el método químico in-situ. El zirconato de bario (BZO) es el material más atractivo para inducir centros de pinning artificiales en las películas delgadas de YBCO, con el fin de aumentar la densidad de corriente crítica. Una caracterización detallada de los nanocompuestos de BaZrO3 (BZO) crecidos por MOD será presentada a través del SEM, XRD y TEM. Referencias [1] Joseph Milton, "Superconductors come of age," Nature (2010). [2] C. Freyhardt Herbert and et al., "Coated conductors and their applications," Superconductor Science and Technology 23 (1), 010201 (2010). [3] "Nespa - NanoEngineered Superconductors for Power Applications," http://www.ifw-dresden.de/nespa.100 years after Dutch physicist Heike Kamerlingh Onnes found that mercury has an electrical resistance of zero when cooled in liquid helium, superconductors are finally being rolled out for use in electricity grids. Superconductive wiring carries about ten times as much power as the same volume of conventional copper wiring. Although some of that power is lost (ac losses) and liquid nitrogen must be used to keep cool the superconducting cables or other devices, such power systems are still more efficient than those based on copper wiring, which losses 7-10% of the power it carries as heat. Because of this, several countries, such as USA, Japan, South Korea, China and Europe have established objectives for 'green' electricity networks reducing the greenhouse gas generation (CO2) and build more efficient and robust 'smart grids' based on the superconductors. The high temperature superconducting wires are made based on the ceramic compound yttrium barium copper oxide (YBCO), part of a family of 'high-temperature' superconducting ceramics that were first discovered in 1986. The attractive perspectives offered by coated conductors, known as the 2nd generation of high temperature superconductors (2G-HTS), have triggered broad and fruitful R&D efforts to make them ready for the market place [2]. Recently, LS Cable, a South Korean company based in Anyang-si near Seoul, has ordered three million meters of superconducting wire from the US firm American Superconductor in Devens, Massachusetts, which is the highest commercial order so far of HTS CC [1]. High Temperature Superconductors (HTS) have an enormous potential for significantly improving existing power systems, such as cables, motors, transformers, magnets and generators, because higher power densities and reduced losses can be achieved by replacing copper or low temperature superconductor wires [3]. Superconducting materials will also enable completely new technologies in the power sector, such as fault current limiters or inherently stable magnetic levitation. As examples for innovative applications, advanced energy systems for “all-electrical” ships, off-shore windmills and transportation systems should be mentioned. Although research on the materials aspects of HTS has been highly successful in the past, the development of low cost - high performance HTS materials remains a key factor of success and, in order to bring these emerging materials onto the market in a reasonable time frame, requires significantly more basic and applied materials research. The main objective of this thesis is to develop new simplified nanostructured Coated Conductors architectures based on Chemical Solution Deposition (CSD). For that, the growth and characterization of these Coated Conductors was investigated first on YSZ single crystals where CeO2-derived cap layer can be easily grown. The knowledge generated can be useful for two types of metallic substrates: 1.- MODLZO buffered Ni5%W RABiTS substrates; 2.- ABADYSZ buffered Stainless Steel (SS) polycrystalline substrates. Taking into account the quality of the existing metallic substrates, this thesis has been concentrated on ABADYSZ/SS substrates, provided by Bruker HTS, Germany. The first step for achieving simplified architectures was the investigation of Gd,Zr doped CeO2 which better adapts to the mentioned substrates. The second step consisted in growing YBa2Cu3O7-x superconducting films using the trifluoracetates route. This work starts with a brief description of the superconductivity, followed by a short introduction about the superconductive compound YBCO and ends with the principal methods for obtaining high quality textured YBCO films. A complete characterization of the samples with various techniques (Atomic Force Microscopy (AFM), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Reflection High-Energy Electron Diffraction (RHEED), Pulsed Laser Deposition (PLD), SQUID, X-ray reflectivity (XRR) and electrical transport measurements) is necessary in order to understand the complex mechanism of each superconductor and the interactions between different layers. Various doped cerium oxide thin films used as cap layer, prepared by spin coating were also investigated. The technical requirements for high quality Coated Conductors are very diverse. To achieve a high quality epitaxy and high Jc, it is necessary to perform a detailed morphological and structural characterization by means of SEM and XRD. This microstructure of the YBCO layer needs to be closely correlated with that of the cap layer. In order to study the superconducting properties in more detail, inductive and transport measurements have been performed to examine current flow in YBCO films deposited on different substrates. The results obtained with CeO2-derived cap layers grown on Alternating Beam Assisted Deposition (ABAD) substrates were also reported. Last part of this thesis is dedicated to the development of BaZrO3-YBa2Cu3O7-x and BaCeO3-YBa2Cu3O7-x nanocomposites thin films by MOD using the in-situ approach. Barium zirconate is the most attractive material to induce artificial pinning centers both in YBCO thin films, in order to increase the critical current density. Detailed characterization by SEM, XRD and TEM of BaZrO3 (BZO) nanocomposite grown by MOD will be presented. References [1] Joseph Milton, "Superconductors come of age," Nature (2010). [2] C. Freyhardt Herbert and et al., "Coated conductors and their applications," Superconductor Science and Technology 23 (1), 010201 (2010). [3] "Nespa - NanoEngineered Superconductors for Power Applications," http://www.ifw-dresden.de/nespa

Growth and characterization of chemical solution based nanostructured coated conductors with CeO(2) cap layers

100 años después de que el físico holandés Heike Kamerlingh Onnes descubriera que el mercurio tiene una resistencia eléctrica igual a cero, cuando se enfría en el helio líquido, los superconductores son lanzados finalmente para su uso en las redes eléctricas. Los cables superconductores pueden transportar diez veces más energía que el mismo volumen de los cables convencionales de cobre. Aunque parte de esta energía se pierde (pérdidas de corriente alterna) y se necesita usar el nitrógeno líquido para enfriar los cables superconductores y otros dispositivos, tales sistemas de energía son mucho más eficientes que las basadas en cableado de cobre, donde las pérdidas de potencia, alrededor de 7-10%, son en forma de calor. Debido a esto, países como EE.UU., Japón, Corea del Sur, China y Europa han establecido objetivos para las redes "verdes" de electricidad, reduciendo la generación de gases de efecto invernadero (CO2) y construyendo "redes inteligentes" basadas en superconductores más eficientes y robustos. Los cables superconductores de alta temperatura están hechos de un óxido de itrio, bario, cobre (YBCO) que forma parte de la familia de las cerámicas superconductoras de "alta temperatura", descubiertas por primera vez en 1986. Las perspectivas atractivas ofrecidas por los conductores recubiertos (Coated Conductors), conocidos como la 2 ª generación de superconductores de alta temperatura (2G-HTS), han dado lugar a amplios y fructíferos esfuerzos de investigación y desarrollo para que estos sean preparados para el mercado [2]. Recientemente, LS Cable, una compañía de Corea del Sur con sede en Anyang-si, cerca de Seúl, ha ordenado tres millones de metros de cable superconductor de la firma American Superconductor desde EE.UU., en Devens, Massachusetts, que es el más alto pedido comercial de HTS CC hasta el momento [1] . Los superconductores de alta temperatura (HTS) tienen un enorme potencial para mejorar significativamente los sistemas de energía existentes, tales como cables, motores, transformadores, imanes y generadores, debido a que se puede alcanzar una mayor densidad de energía y se pueden reducir las pérdidas, comparado con los cables de cobre o cables superconductores de baja temperatura [3]. Los materiales superconductores abren tecnologías completamente nuevas en el sector de la energía, tales como limitadores de corriente o de levitación magnética inherentemente estable. Como ejemplos de aplicaciones innovadoras, deben ser mencionados sistemas avanzados de energía para barcos "all-electrical", molinos de viento en la costa y sistemas de transporte. Aunque la investigación sobre materiales HTS ha tenido mucho éxito en el pasado, el desarrollo de materiales superconductores de bajo coste sigue siendo un factor clave de éxito y, a fin de traer estos materiales emergentes en el mercado en un plazo razonable, requiere una investigación de materiales mucho más básica y aplicada. El objetivo principal de esta tesis, es el desarrollo de nuevas arquitecturas simplificadas nanoestructuradas de Coated Conductors, basadas en la deposición de soluciones químicas (CSD). Para ello, el crecimiento y la caracterización de estos Coated Conductors, se ha investigado primero sobre monocristales de YSZ, donde el CeO2 se puede crecer fácilmente como tapa tampón. El conocimiento generado puede ser útil para dos tipos de sustratos metálicos: 1.- sustratos Ni5%W RABiTS con MODLZO como capa tampón; 2.- sustratos policristalinos de Stainless Steel (SS) con ABADYSZ como capa tampón. Teniendo en cuenta la calidad de los sustratos metálicos existentes, esta tesis se ha concentrado en los sustratos policristalinos de Stainless Steel (SS), enviados por la empresa alemana Bruker HTS. El primer paso para obtener arquitecturas simplificadas fue la investigación del oxido de cerio dopado con Gd y Zr que mejor se adapta a los sustratos mencionados. El segundo paso consistió en crecer películas delgadas superconductoras de YBa2Cu3O7-x, con la ruta de los trifluoracetatos. Este trabajo comienza con una breve descripción de la superconductividad, seguido por una breve introducción sobre el compuesto superconductor YBCO y termina con los principales métodos para la obtención de películas de YBCO texturadas de alta calidad. Una caracterización completa de las muestras con diversas técnicas (Microscopía de fuerza atómica (AFM), Difracción de rayos X (DRX), Microscopía Electrónica de Barrido (SEM), Microscopía Electrónica de Transmisión (TEM), Difracción de electrones rasantes (RHEED), Deposición con láser pulsado (PLD), SQUID, Reflectividad de rayos X (XRR) y medidas eléctricas de transporte) es necesaria para comprender el mecanismo complejo de cada superconductor y las interacciones entre las diferentes capas. Han sido investigadas varias películas de óxido de cerio dopado usado como capa tampón superior, preparadas por spin coating. Los requisitos técnicos para obtener Coated Conductors de alta calidad son muy diversos. Para lograr una epitaxia de alta calidad y alta Jc, es necesario llevar a cabo una detallada caracterización morfológica y estructural por medio de SEM y DRX. La microestructura de la capa de YBCO debe estar estrechamente correlacionada con la de la capa tampón. Para estudiar más en detalle las propiedades superconductoras, se han realizado medidas inductivas y de transporte para examinar el flujo de corriente en las películas de YBCO depositadas sobre distintos sustratos. Los resultados obtenidos con las capas de CeO2 crecidas sobre ABADYSZ/SS han sido reportados. La última parte de esta tesis está dedicada al desarrollo de películas delgadas de materiales nanocompuestos de MODBaZrO3-YBa2Cu3O7-x y MODBaCeO3-YBa2Cu3O7-x usando el método químico in-situ. El zirconato de bario (BZO) es el material más atractivo para inducir centros de pinning artificiales en las películas delgadas de YBCO, con el fin de aumentar la densidad de corriente crítica. Una caracterización detallada de los nanocompuestos de BaZrO3 (BZO) crecidos por MOD será presentada a través del SEM, XRD y TEM. Referencias [1] Joseph Milton, "Superconductors come of age," Nature (2010). [2] C. Freyhardt Herbert and et al., "Coated conductors and their applications," Superconductor Science and Technology 23 (1), 010201 (2010). [3] "Nespa - NanoEngineered Superconductors for Power Applications," http://www.ifw-dresden.de/nespa.100 years after Dutch physicist Heike Kamerlingh Onnes found that mercury has an electrical resistance of zero when cooled in liquid helium, superconductors are finally being rolled out for use in electricity grids. Superconductive wiring carries about ten times as much power as the same volume of conventional copper wiring. Although some of that power is lost (ac losses) and liquid nitrogen must be used to keep cool the superconducting cables or other devices, such power systems are still more efficient than those based on copper wiring, which losses 7-10% of the power it carries as heat. Because of this, several countries, such as USA, Japan, South Korea, China and Europe have established objectives for 'green' electricity networks reducing the greenhouse gas generation (CO2) and build more efficient and robust 'smart grids' based on the superconductors. The high temperature superconducting wires are made based on the ceramic compound yttrium barium copper oxide (YBCO), part of a family of 'high-temperature' superconducting ceramics that were first discovered in 1986. The attractive perspectives offered by coated conductors, known as the 2nd generation of high temperature superconductors (2G-HTS), have triggered broad and fruitful R&D efforts to make them ready for the market place [2]. Recently, LS Cable, a South Korean company based in Anyang-si near Seoul, has ordered three million meters of superconducting wire from the US firm American Superconductor in Devens, Massachusetts, which is the highest commercial order so far of HTS CC [1]. High Temperature Superconductors (HTS) have an enormous potential for significantly improving existing power systems, such as cables, motors, transformers, magnets and generators, because higher power densities and reduced losses can be achieved by replacing copper or low temperature superconductor wires [3]. Superconducting materials will also enable completely new technologies in the power sector, such as fault current limiters or inherently stable magnetic levitation. As examples for innovative applications, advanced energy systems for "all-electrical" ships, off-shore windmills and transportation systems should be mentioned. Although research on the materials aspects of HTS has been highly successful in the past, the development of low cost - high performance HTS materials remains a key factor of success and, in order to bring these emerging materials onto the market in a reasonable time frame, requires significantly more basic and applied materials research. The main objective of this thesis is to develop new simplified nanostructured Coated Conductors architectures based on Chemical Solution Deposition (CSD). For that, the growth and characterization of these Coated Conductors was investigated first on YSZ single crystals where CeO2-derived cap layer can be easily grown. The knowledge generated can be useful for two types of metallic substrates: 1.- MODLZO buffered Ni5%W RABiTS substrates; 2.- ABADYSZ buffered Stainless Steel (SS) polycrystalline substrates. Taking into account the quality of the existing metallic substrates, this thesis has been concentrated on ABADYSZ/SS substrates, provided by Bruker HTS, Germany. The first step for achieving simplified architectures was the investigation of Gd,Zr doped CeO2 which better adapts to the mentioned substrates. The second step consisted in growing YBa2Cu3O7-x superconducting films using the trifluoracetates route. This work starts with a brief description of the superconductivity, followed by a short introduction about the superconductive compound YBCO and ends with the principal methods for obtaining high quality textured YBCO films. A complete characterization of the samples with various techniques (Atomic Force Microscopy (AFM), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Reflection High-Energy Electron Diffraction (RHEED), Pulsed Laser Deposition (PLD), SQUID, X-ray reflectivity (XRR) and electrical transport measurements) is necessary in order to understand the complex mechanism of each superconductor and the interactions between different layers. Various doped cerium oxide thin films used as cap layer, prepared by spin coating were also investigated. The technical requirements for high quality Coated Conductors are very diverse. To achieve a high quality epitaxy and high Jc, it is necessary to perform a detailed morphological and structural characterization by means of SEM and XRD. This microstructure of the YBCO layer needs to be closely correlated with that of the cap layer. In order to study the superconducting properties in more detail, inductive and transport measurements have been performed to examine current flow in YBCO films deposited on different substrates. The results obtained with CeO2-derived cap layers grown on Alternating Beam Assisted Deposition (ABAD) substrates were also reported. Last part of this thesis is dedicated to the development of BaZrO3-YBa2Cu3O7-x and BaCeO3-YBa2Cu3O7-x nanocomposites thin films by MOD using the in-situ approach. Barium zirconate is the most attractive material to induce artificial pinning centers both in YBCO thin films, in order to increase the critical current density. Detailed characterization by SEM, XRD and TEM of BaZrO3 (BZO) nanocomposite grown by MOD will be presented. References [1] Joseph Milton, "Superconductors come of age," Nature (2010). [2] C. Freyhardt Herbert and et al., "Coated conductors and their applications," Superconductor Science and Technology 23 (1), 010201 (2010). [3] "Nespa - NanoEngineered Superconductors for Power Applications," http://www.ifw-dresden.de/nespa

Inkjet printed multi-deposited YBCO on CGO/LMO/MgO/Y2O3/Al2O3/Hastelloy tape for 2G Coated Conductors

Vlad, Valentina Roxana et al.We present the preparation of a new architecture of coated conductor by Inkjet printing of low fluorine YBa2Cu3O7-x on top of SuperOx tape: CGO/LMO/IBAD-MgO/Y2O3/Al2O3/Hastelloy. A 5-layered multi-deposited, 475 nm thick YBCO film was structurally and magnetically characterized. A good texture was achieved using this combination of buffer layers, requiring only a 30 nm thin IBAD-MgO layer. The LF-YBCO CC reaches self-field critical current density values of JcGB~15.9 MA/cm2 (5 K), ~1.23 MA/cm2 (77 K) corresponding to an Ic(77K)=58.4 A/cm-width. Inkjet printing offers a flexible and cost effective method for YBCO deposition, allowing patterning of structures.This work was performed within the framework of the EUROTAPES project (FP7-NMP.2011.2.2-1 Grant no. 280432), funded by the EU. ICMAB research was financed by the Ministry of Economy and Competitiveness, and FEDER funds under projects MAT2011-28874-C02-01, MAT2014-51778-C2-1-R, ENE2014-56109-C3-3-R and Consolider Nanoselect CSD2007-00041, and by Generalitat de Catalunya (2009 SGR 770, 2015 SGR 753 and Xarmae). ICMAB acknowledges support from Severo Ochoa Program (MINECO, Grant SEV-2015-0496).Peer reviewe