An IAEA Multi-technique X-ray Spectrometry End-station at Elettra Sincrotrone Trieste: Benchmarking Results and Interdisciplinary Applications

The International Atomic Energy Agency (IAEA) jointly with the Elettra Sincrotrone Trieste (EST) operates a multipurpose X-ray spectrometry endstation at the X-ray Fluorescence beamline (10.1L). The facility has been available to external users since the beginning of 2015 through the peer-review process of EST. Using this collaboration framework, the IAEA supports and promotes synchrotron-radiation-based research and training activities for various research groups from the IAEA Member States, especially those who have limited previous experience and resources to access a synchrotron radiation facility. This paper aims to provide a broad overview about various analytical capabilities, intrinsic features and performance figures of the IAEA X-ray spectrometry endstation through the measured results. The IAEA-EST endstation works with monochromatic X-rays in the energy range 3.7-14keV for the Elettra storage ring operating at 2.0 or 2.4GeV electron energy. It offers a combination of different advanced analytical probes, e.g. X-ray reflectivity, X-ray absorption fine-structure measurements, grazing-incidence X-ray fluorescence measurements, using different excitation and detection geometries, and thereby supports a comprehensive characterization for different kinds of nanostructured and bulk materials.A broad overview of the various analytical capabilities, intrinsic features and performance figures of the IAEA X-ray spectrometry endstation operated at the X-ray Fluorescence beamline of Elettra Sincrotrone Trieste is given, and different applications are demonstrated to familiarize the user community with the applicable intersdisciplinary research.Fil: Karydas, A.. International Atomic Energy Agency; Austria. National Centre for Scientific Research "Demokritos"; GreciaFil: Czyzycki, M.. International Atomic Energy Agency; Austria. AGH University of Science and Technology. Faculty of Physics and Applied Computer Science ; PoloniaFil: Leani, Juan Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Física Enrique Gaviola. Universidad Nacional de Córdoba. Instituto de Física Enrique Gaviola; Argentina. International Atomic Energy Agency; AustriaFil: Migliori, A.. International Atomic Energy Agency; Austria. Nuclear Spectrometry And Appications Lab, Iaea. Onu; AustriaFil: Osán, J.. Hungarian Academy of Sciences Centre for Energy Research; Hungría. International Atomic Energy Agency; AustriaFil: Bogovac, M.. International Atomic Energy Agency; AustriaFil: Wrobel, P.. AGH University of Science and Technology. Faculty of Physics and Applied Computer Science ; PoloniaFil: Vakula, N.. International Atomic Energy Agency; AustriaFil: Padilla Alvarez, R.. International Atomic Energy Agency; AustriaFil: Menk, Ralf Hendrik. Elettra-Sincrotrone Trieste SCpA di Interesse Nazionale; Italia. University of Saskatchewan; CanadáFil: Gol, M. G.. Iranian Light Source Facility; IránFil: Antonelli, M.. Istituto Nazionale di Fisica Nucleare; Italia. Elettra-Sincrotrone Trieste SCpA di Interesse Nazionale; ItaliaFil: Tiwari, M. K.. Raja Ramanna Centre for Advanced Technology; IndiaFil: Caliri, C.. Istituto Nazionale di Fisica Nucleare; ItaliaFil: Vogel Mikuš, K.. Jozef Stefan Institute; Eslovenia. University of Ljubljana; EsloveniaFil: Darby, I.. Elettra-Sincrotrone Trieste SCpA di Interesse Nazionale; Italia. International Atomic Energy Agency; AustriaFil: Kaiser, R.. International Atomic Energy Agency; Austri

Application Of Nano-Imprint Lithography For Next Generation Carbon Nanotube-Based Devices

This research report addresses the development of 3D carbon nanostructures that can provide unique capabilities for manufacturing carbon nanotube (CNT) electronic components, electrochemical probes, biosensors and tissue scaffolds. The shaped CNT arrays were grown on patterned catalytic substrate by chemical vapor deposition (CVD) method. The new fabrication process for catalyst patterning based on combination of nano-imprint lithography (NIL), magnetron sputtering and reactive etching techniques was proposed and studied. The optimal process parameters for each technique were evaluated. The catalyst was made by deposition of Fe and Co nanoparticles over alumina support layer on Si/SiO2 substrate. The metal particles were deposited using direct current (DC) magnetron sputtering technique, with the particles size from 6 nm to 12 nm and density from 70 to 1000 particles/micron2. Alumina layer was deposited by radio frequency (RF) and reactive pulsed DC sputtering, and the effect of sputtering parameters on surface roughness was studied. The pattern was developed by thermal NIL using Si master-molds and PMMA and NRX1025 polymers as a thermal resists. Catalyst patterns of lines, dots and holes ranging from 70 nm to 500 nm were produced and characterized by scanning electron microscopy (SEM) and atomic force microscopies (AFM). Vertically aligned CNTs were successfully grown on patterned catalyst and their quality was evaluated by SEM and micro-Raman. The results confirm that the new fabrication process has ability to control the size and shape of CNT arrays without loss of their quality

Ald processes development for hybrid nanodevices-like nanostructures

194 p.The development of new and innovative atomic structures displaying multifunctional properties goes together with progress in advanced processes which enable atomic level control. One leading deposition technique is Atomic layer deposition (ALD), which has emerged as a powerful tool for bond-specific functionalization and the growth of stoichiometric films over wafer scale and high area uniformity. ALD offers a wide range of functionalization routes by means of four processes such as vapor phase metalation (VPM), multiple pulsed vapor-phase infiltration (MPI), ALD and molecular layer deposition (MLD). As an example of VPM on soft molecules, Zn metalation on Enterobactin (H6EB) and FeEnterobactin (FeH3EB) were studied experimentally and theoretically. Thus, we showed that the VPM process could become a route to functionalize soft organic molecules with potential applications in the pharmaceutical field. Extending Zn metalation-VPM growth to hybrid nanostructures, in this case ML-(NH4)V7O16. nanostructured square and Mw-H2Ti3O7 nanotubes. Zn metalation-VPM process provides a way to functionalize soft nanostructured materials in order to change their crystal structure and thereby their magnetic and optical properties, without affect their morphology. The use of DEZn/H2O in MPI, promotes the nucleation of ZnO nanoparticles around the nanotube (cactus-like) affecting the morphology and surface properties. It was found that the electronic energy gap decreases with increasing Zn content, making the (ZnO)Ti3O7 nanoparticle/nanotube nanocomposites potentially useful as photoanode for dye-sensitized solar cells (DSCs) and sensors. The ALD growth of uniform MxOy thin films where M stands for V, Mn, Sn or Zn was undertaken. The preliminary results show successful deposition of ¿-MnO2, ¿-V2O5, SnxOy and ZnO stoichiometric films, uniform over large areas. This points towards the possible growth of these oxides which can be considered as energy materials. Finally, the growth of alucone thin films (AlO-T and AlO-A, T: terephthalate and A: adipate) by ALD and MLD was explored. Stoichiometric thin films with large area uniformity were obtained in both cases. The use of bifunctional monomers (aromatic and aliphatic carboxylate) in the growth of AlO-T and AlO-A thin films leads to a lamellar phase and to an amorphous one, respectively. The structure of AlO-T is obtained by optimizing four models and correlating experimental data with DFT calculations. The analysis of the electronic band gap using frontier orbital (HOMO-LUMO), alongside the uniform LiPF6 distribution through the AlO-T, point to future studies of AlO-T for anode and electrolyte nanomembranes with potential applications in carboxylates-based energy storage concepts. Thus, in this thesis we have shown the versatility of ALD processes to realize novel thin films and pursue various functionalization strategies

Ald processes development for hybrid nanodevices-like nanostructures

194 p.The development of new and innovative atomic structures displaying multifunctional properties goes together with progress in advanced processes which enable atomic level control. One leading deposition technique is Atomic layer deposition (ALD), which has emerged as a powerful tool for bond-specific functionalization and the growth of stoichiometric films over wafer scale and high area uniformity. ALD offers a wide range of functionalization routes by means of four processes such as vapor phase metalation (VPM), multiple pulsed vapor-phase infiltration (MPI), ALD and molecular layer deposition (MLD). As an example of VPM on soft molecules, Zn metalation on Enterobactin (H6EB) and FeEnterobactin (FeH3EB) were studied experimentally and theoretically. Thus, we showed that the VPM process could become a route to functionalize soft organic molecules with potential applications in the pharmaceutical field. Extending Zn metalation-VPM growth to hybrid nanostructures, in this case ML-(NH4)V7O16. nanostructured square and Mw-H2Ti3O7 nanotubes. Zn metalation-VPM process provides a way to functionalize soft nanostructured materials in order to change their crystal structure and thereby their magnetic and optical properties, without affect their morphology. The use of DEZn/H2O in MPI, promotes the nucleation of ZnO nanoparticles around the nanotube (cactus-like) affecting the morphology and surface properties. It was found that the electronic energy gap decreases with increasing Zn content, making the (ZnO)Ti3O7 nanoparticle/nanotube nanocomposites potentially useful as photoanode for dye-sensitized solar cells (DSCs) and sensors. The ALD growth of uniform MxOy thin films where M stands for V, Mn, Sn or Zn was undertaken. The preliminary results show successful deposition of ¿-MnO2, ¿-V2O5, SnxOy and ZnO stoichiometric films, uniform over large areas. This points towards the possible growth of these oxides which can be considered as energy materials. Finally, the growth of alucone thin films (AlO-T and AlO-A, T: terephthalate and A: adipate) by ALD and MLD was explored. Stoichiometric thin films with large area uniformity were obtained in both cases. The use of bifunctional monomers (aromatic and aliphatic carboxylate) in the growth of AlO-T and AlO-A thin films leads to a lamellar phase and to an amorphous one, respectively. The structure of AlO-T is obtained by optimizing four models and correlating experimental data with DFT calculations. The analysis of the electronic band gap using frontier orbital (HOMO-LUMO), alongside the uniform LiPF6 distribution through the AlO-T, point to future studies of AlO-T for anode and electrolyte nanomembranes with potential applications in carboxylates-based energy storage concepts. Thus, in this thesis we have shown the versatility of ALD processes to realize novel thin films and pursue various functionalization strategies

Inorganic Nanostructures Prepared by Electrospinning and Atomic Layer Deposition

Nanostructures are structures where at least one dimension is in nanoscale which ranges typically from 1 to 100 nm. 1D nanostructure is an object where two dimensions are in the nanometer scale and one dimension in a larger scale, for example carbon nanotubes and electrospun fibers. Due to a very small size, nanostructured materials have different properties than what they have in bulk form, for example chemical reactivity is increased when the size comes smaller. Electrospinning is a very simple but versatile and scalable method for preparing micro- and nanosized fibers. In an electrospinning process an electrical charge is used to spin very fine fibers from a polymer solution or melt. By changing electrospinning parameters, for example voltage and spinneret-collector distance, fibers of different diameters can be obtained. With different electrospinning setups it is also possible to prepare hollow fibers, and even macroscopic objects with fiber walls can be obtained. This work was concentrated on A) constructing different electrospinning setups and verifying their operation by electrospinning various materials, and B) preparing 1D nanostructures like inorganic nanofibers directly by electrospinning and nanotubes by combining electrospinning and atomic layer deposition, ALD. This is so called Tubes by Fiber Template (TUFT) –process. The electrospinning setup was constructed successfully, and its operation was verified. Several materials were electrospun. Polymers (PVP, PVA, PVAc, PEO, PMMA and PVB, Chitosan) were electrospun directly from polymer/solvent solution, and ceramic materials like TiO2, BaTiO3, SnO2, CuO, IrO2, ZnO, Fe2O3, NiFe2O4, CoFe2O4, SiO2 and Al2O3 were electrospun from polymer solutions containing the corresponding metal precursor(s). In the case of the ceramic fibers, the electrospinning was followed by calcination to remove the polymer part of the fibers. Metallic fibers were obtained by a reduction treatment of the corresponding oxides, for example Ir fibers were prepared by reducing IrO2 fibers. Combination of electrospinning and ALD was used for TUFT processing of ceramic nanotubes. In the TUFT process, electrospun template fibers were coated with the desired material (Al2O3, TiO2, IrO2, Ir, PtOx and Pt) and after coating the template fibers were removed by calcination. The inner diameter of the resulting tubes was determined by the template fiber and the tube wall thickness by the thickness of the ALD deposited film. Promising results were obtained in searching for new applications for electrospun fibers. For the first time, by combining electrospinning and ALD, the TUFT process was used to prepare reusable magnetic photocatalyst fibers. These fibers have a magnetic core fiber and a photocatalytic shell around it. After a photocatalyst purification was completed, the fibers could be collected from the solution by a strong magnet and reused in cleaning the next solution. In this study, the most commercially and environmentally valuable application invented was to use electrospun ion selective sodium titanate nanofibers for purification of radioactive wastewater. These fibers were found to be more efficient than commercial granular products, and they need much less space in final disposal.Nanorakenteita tutkitaan maailmalla kiihtyvällä tahdilla. Nanorakenteeksi määritellään rakenne, jossa vähintään yksi ulottuvuus on nanomittakaavassa (1 - 100 nm). Kuitua, jonka halkaisija on nanomittakaavassa, kutsutaan nanokuiduksi ja kalvoa vastaavasti ohutkalvoksi. Tässä väitöskirjatyössä tutkittiin epäorgaanisten nanorakenteiden, kuten kuitujen ja putkien valmistusta sähkökehräys ja atomikerroskasvatusmenetelmillä (ALD, Atomic Layer Deposition) ja kehitettiin valmistetuille rakenteille mahdollisia sovelluskohteita. Sähkökehräys on menetelmä, jossa sähkökentän avulla polymeeriliuoksesta saadaan kehrättyä polymeerisiä ja keraamisia nanokuituja. ALD-menetelmä on puolestaan ohutkalvomenetelmä, jossa materiaali kasvatetaan kohdemateriaalin pinnalle atomikerroksittain, kun reagoivat kaasumaiset lähtöaineet tuodaan pinnalle vuorotellen yksi kerrallaan. Kalvon paksuus riippuu syklien määrästä. Väitöskirjatyön yhtenä tavoitteena oli kehittää erilaisia sähkökehräyslaitteistoja. Kehitettyjen laitteiden toiminta varmennettiin kehräämällä eri kuitumateriaaleja, kuten polymeerejä, keraameja ja metalleja. Tutkimuksessa valmistettiin myös nanoputkia yhdistämällä sähkökehräys- ja ALD-menetelmät. Menetelmässä kehrätyn polymeerikuidun pinnalle kasvatettiin ALD-ohutkalvo, jonka jälkeen mallina toiminut polymeerikuitu poistettiin. Putken sisähalkaisija määräytyy kuidun paksuuden mukaan ja putken seinämien paksuus puolestaan ALD-ohutkalvon paksuuden mukaan. Väitöskirjatyö osoitti, että sähkökehrättyjen kuitujen yksi mahdollisista ja ehkä tärkeimmistäkin sovelluskohteista on jätevesien puhdistus. Työn aikana kehitettyjä magneettisia fotokatalyyttikuituja voidaan käyttää useita kertoja. Kuidun ydin on sähkökehrätty magneettinen kuitu ja ulkokuori ALD:llä valmistettu fotokatalyyttinen ulkokuori. Kuidut voidaan kerätä liuoksesta magneetilla ja samoja kuituja voidaan käyttää uudelleen myös seuraavassa puhdistettavassa liuoksessa. Magneettisten fotokatalyyttikuitujen lisäksi tutkimuksen toinen merkittävä tulos on työn aikana kehitetty ioniselektiivinen ioninvaihtokuitu radioaktiivisten jätevesien puhdistamiseen. Valmistetut kuidut todettiin huomattavasti tehokkaammaksi kuin vastaavat kaupalliset raemaiset tuotteet. Sähkökehrätyn ioninvaihtokuidut ovat raemaisia materiaaleja tehokkaampia ja tarvitsevat tehokkuutensa ja pienemmän tilavuutensa vuoksi vähemmän tilaa ydinjätteiden loppusijoituksessa

Pulsed Laser Deposition of WOx and FeOx thin films

The deposition of WOx and FeOx thin films by reactive PLD and post-deposition annealing in an oxygen environment have been investigated. The influence of the deposition parameters on the growth and structure of WOx as well as the electronic and structural properties of FeOx thin films are presented. WOx thin films have been deposited onto native oxide Si (100) and SrTiO3 (100) substrates, whilst FeOx films were deposited onto glass and MgO (100). The films have been analysed using X-ray diffraction (XRD), texture pole figure analysis, X-ray reflectivity (XRR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), atomic force microscopy (AFM) and resistance vs temperature measurements. The WOx films deposited on both Si and SrTiO3 substrates were found to exhibit a dependence on the primary texture with fluence in the range of 5.3 J cm-2 to 14.7 J cm-2. The WOx films deposited on SrTiO3 were observed to exhibit a biaxial texture whilst the films on Si displayed a (002) WO3 out of plane fibre texture. The primary texture of the WOx films on SrTiO3 was observed to evolve from (200)/(020) WO3 to a single (002) WO3 texture with increasing fluence. The FeOx films deposited via reactive PLD onto glass substrates were found to exist in the Fe2O3 oxidation state for all parameters used. The production of Fe3O4 by post-deposition annealing of Fe films on glass and MgO (100) substrates in an oxygen environment is also presented. On both substrates it was necessary to use a two-stage anneal process to produce Fe3O4; an initial 175 °C oxygen anneal followed by a 500 °C vacuum anneal. The presence of Fe3O4 was confirmed by the existence of the Verwey transition at close to 120 K, during resistance vs temperature scans. The anneal parameters required to produce Fe3O4 are shown to be different for MgO substrates in comparison to glass

Estudo de materiais multiferroicos

Doutoramento em FísicaThe present PhD work aims the research and development of materials that exhibit multiferroic properties, in particular having a significant interaction between ferromagnetism and ferroelectricity; either directly within an intrinsic single phase or by combining extrinsic materials, achieving the coupling of properties through mechanic phenomena of the respective magnetostriction and piezoelectricity. These hybrid properties will allow the cross modification of magnetic and electric polarization states by the application of cross external magnetic and/or electric fields, giving way to a vast area for scientific investigation and potential technological applications in a new generation of electronic devices, such as computer memories, signal processing, transducers, sensors, etc. Initial experimental work consisted in chemical synthesis of nano powders oxides by urea pyrolysis method: A series of ceramic bulk composites with potential multiferroic properties comprised: of LuMnO3 with La0.7Sr0.3MnO3 and BaTiO3 with La0.7Ba0.3MnO3; and a series based on the intrinsic multiferroic LuMn1-zO3 phase modified with of Manganese vacancies. The acquisition of a new magnetron RF sputtering deposition system, in the Physics Department of Aveiro University, contributed to the proposal of an analogous experimental study in multiferroic thin films and multilayer samples. Besides the operational debut of this equipment several technical upgrades were completed like: the design and construction of the heater electrical contacts; specific shutters and supports for the magnetrons and for the substrate holder and; the addition of mass flow controllers, which allowed the introduction of N2 or O2 active atmosphere in the chamber; and the addition of a second RF generator, enabling co-deposition of different targets. Base study of the deposition conditions and resulting thin films characteristics in different substrates was made from an extensive list of targets. Particular attention was given to thin film deposition of magnetic phases La1-xSrxMnO3, La1-xBaxMnO3 and Ni2+x-yMn1-xGa1+y alloy, from the respective targets: La0.7Sr0.3MnO3, La0.7Ba0.3MnO3; and NiGa with NiMn. Main structural characterization of samples was performed by conventional and high resolution X-Ray Diffraction (XRD); chemical composition was determined by Electron Dispersion Spectroscopy (EDS); magnetization measurements recur to a Vibrating Sample Magnetometer (VSM) prototype; and surface probing (SPM) using Magnetic-Force (MFM) and Piezo-Response (PFM) Microscopy. Results clearly show that the composite bulk samples (LuM+LSM and BTO+LBM) feat the intended quality objectives in terms of phase composition and purity, having spurious contents below 0.5 %. SEM images confirm compact grain packaging and size distribution around the 50 nm scale. Electric conductivity, magnetization intensity and magneto impedance spreading response are coherent with the relative amount of magnetic phase in the sample. The existence of coupling between the functional phases is confirmed by the Magnetoelectric effect measurements of the sample “78%LuM+22%LSM” reaching 300% of electric response for 1 T at 100 kHz; while in the “78%BTO+22%LBM” sample the structural transitions of the magnetic phase at ~350 K result in a inversion of ME coefficient the behavior. A functional Magneto-Resistance measurement system was assembled from the concept stage until the, development and operational status; it enabled to test samples from 77 to 350 K, under an applied magnetic field up to 1 Tesla with 360º horizontal rotation; this system was also designed to measure Hall effect and has the potential to be further upgraded. Under collaboration protocols established with national and international institutions, complementary courses and sample characterization studies were performed using Magneto-Resistance (MR), Magneto-Impedance (MZ) and Magneto-Electric (ME) measurements; Raman and X-ray Photoelectron Spectroscopy (XPS); SQUID and VSM magnetization; Scanning Electron Microscopy (SEM) and Rutherford Back Scattering (RBS); Scan Probe Microscopy (SPM) with Band Excitation Probe Spectroscopy (BEPS); Neutron Powder Diffraction (NPD) and Perturbed Angular Correlations (PAC). Additional collaboration in research projects outside the scope of multiferroic materials provided further experience in sample preparation and characterization techniques, namely VSM and XPS measurements were performed in cubane molecular complex compounds and enable to identify the oxidation state of the integrating cluster of Ru ions; also, XRD and EDS/SEM analysis of the acquired targets and substrates implied the devolution of some items not in conformity with the specifications. Direct cooperation with parallel research projects regarding multiferroic materials, enable the assess to supplementary samples, namely a preliminary series of nanopowder Y1-x-yCaxØyMn1O3 and of Eu0.8Y0.2MnO3, a series of micropowder composites of LuMnO3 with La0.625Sr0.375MnO3 and of BaTiO3 with hexagonal ferrites; mono and polycrystalline samples of Pr1-xCaxMnO3, La1-xSrxMnO3 and La1-xCaxMnO3.O trabalho de doutoramento presente tem por objectivo a pesquisa e desenvolvimento de materiais que manifestem propriedades multiferróicas, em particular com uma significativa interacção entre os fenómenos de ferromagnetismo e ferroelectricidade; seja de forma intrínseca em determinados materiais singulares, ou extrínseca ao combinar materiais que apresentam respectivamente fenómenos magnetoestritivo e de piezoelectricidade e em que geralmente o acoplamento se processa mecanicamente entre as fases. Esta hibridação de propriedades permite a modificação dos estados de polarização magnética ou eléctrica por aplicação dos campos externos complementares (eléctricos e/ou magnéticos), dando origem a uma vasta área de investigação científica e potenciais aplicações tecnológicas numa nova geração de dispositivos electrónicos como memórias, processadores, transdutores, sensores, etc. O trabalho experimental inicial consistiu na síntese química de óxidos sob a forma de pós nanométricos, pelo método de pirólise da ureia; As séries de compósitos maciços com potenciais propriedades multiferróicas compreendem: LuMnO3 com La0.7Sr0.3MnO3 e BaTiO3 com La0.7Ba0.3MnO3; e uma série baseada na modificação com lacunas de Manganésio da fase multiferróica intrínseca LuMn1-zO3. A aquisição de um novo sistema de deposição por RF sputtering, no Departamento de Física da Universidade de Aveiro, contribuiu para a proposta de estudo análogo de amostras multiferróicas sob a forma de filmes finos e multicamadas. Além da estreia operacional do equipamento foram efectuadas algumas melhorias técnicas e funcionais de que se destacam: o desenho e construção das ligações eléctricas do aquecedor; de portadas, protecções e respectivos suportes para os magnetrões e para o “porta substratos”; a adição de dois controladores de fluxo de gás permitindo a introdução controlada de Árgon e de atmosfera activa de O2 ou N2 durante a deposição; e a adição de uma segunda fonte e controlador RF permitindo a co-deposição simultânea de filmes a partir de dois alvos diferentes. O estudo base sobre as condições de deposição e das características dos filmes finos resultantes em diferentes substratos foi efectuada a partir de uma extensa lista de alvos. Atenção particular foi dada à deposição de filmes finos das fases magnéticas de La1-xSrxMnO3, La1-xBaxMnO3 e da liga Ni2+x-yMn1-xGa1+y a partir dos correspondentes alvos La0.7Sr0.3MnO3; La0.7Ba0.3MnO3 e NiGa com NiMn. A caracterização estrutural das amostras foi efectuada com Difractometria por Raios-X (XRD) convencional e de elevada resolução; determinação da composição química foi essencialmente realizada por Espectroscopia de Dispersão de Electrões (EDS); medidas de magnetização foram executadas com recurso a um protótipo de Magnetometro por Vibração da Amostra (VSM) e as medidas de análise de superfície utilizaram Microscopia de Ponta (SPM) nas vertentes de piezo resposta (PFM) e de força magnética (MFM). Os resultados obtidos nos compósitos maciços (LuM+LSM e BTO+LBM) demonstram claramente que as amostras satisfazem os objectivos propostos em termos de composição pureza das fases, com eventual conteúdo em óxidos espúrios inferior a 0.5%. Imagens obtidas por SEM confirmam a compactação dos grãos e distribuição de tamanhos em torno dos 50 nm. Condutividade eléctrica, intensidade da magnetização e a dispersão da resposta em Magneto-Impedância são coerentes com a proporção relativa da fase magnética em cada amostra. A existência de um acoplamento entre as fases funcionais é evidenciada por medidas de efeito Magneto-Eléctrico na amostra “78%LuM+22%LSM” que apresenta uma resposta eléctrica de ~300% para 1 Tesla a 100 kHz; enquanto que na amostra “78%BTO+22%LBM” se assinala a transição estrutural da fase magnética a ~350 K resulta na inversão do comportamento do coeficiente ME. Um sistema de Medidas de Magneto-Resistência foi totalmente desenvolvido e montado desde a fase conceptual até ao estado operacional; permite testar amostras de 77 a 350 K em função do campo magnético até 1 Tesla, e rotação horizontal de 360º; o sistema foi também desenhado para poder efectuar medidas de efeito de Hall e permitir upgrades. Ao abrigo de protocolos de colaboração estabelecidos com diversas instituições nacionais e internacionais, foram realizados cursos de formação complementar e caracterização de amostras em técnicas como Magneto Resistência (MR), Magneto Impedância (MZ) e efeito Magneto Eléctrico (ME); Espectroscopia Raman e Fotoelectrónica de Raios-X (XPS); Magnetização via sistemas SQUID e VSM; Microscopia de Ponta em Piezo resposta (PFM) e Espectroscopia de excitação em largura de banda (BEPS); Espectroscopia de Rutherford por Retro dispersão (RBS); Difracção de Neutrões em pós (NPD) e Correlações de Perturbação Angular (PAC) Colaboração em projectos de investigação fora do âmbito dos materiais multiferróicos permitiu ampliar e versatilizar experiencia em técnicas de preparação e caracterização de amostras, nomeadamente medidas de VSM e XPS permitiram identificar os estados de oxidação dos clusters de iões de Ruténio que integram complexos moleculares utilizados em catalisadores; A certificação por XRD e SEM/EDS do conjunto dos alvos e amostragem dos substratos adquiridos implicou a devolução de alguns itens com por falta de conformidade com as especificações. Cooperação directa em projectos de investigação paralelos sobre materiais multiferróicos permitiu o acesso a amostras suplementares, nomeadamente a uma série nano pós de Y1-x-yCaxØyMn1O3 e de Eu0.8Y0.2MnO3; a series de compósitos microestruturados de LuMnO3 com La0.625Sr0.375MnO3 e de BaTiO3 com ferrites hexagonais; e a diversas amostras poli- e mono-cristalinas de Pr1-xCaxMnO3, La1-xSrxMnO3 e La1-xCaxMnO3.FCT - SFRH/BD/25011/200

Functional Ceramic Coatings

Ceramic materials in the form of coatings can significantly improve the functionality and applications of other engineering materials. Due to a wide range of controllable features and various deposition methods, it is possible to create tailored substrate–coating systems that meet the requirements of modern technologies. Therefore, it is crucial to understand the relationships between the structures, morphology and the properties of ceramic coatings and expand the base of scientific knowledge about them. This book contains a series of fourteen articles which present research on the production and properties of ceramic coatings designed to improve functionality for advanced applications