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Carbon doping is studied in MgB2 pellets during one-step synthesis by solid-state reaction, employing both undoped and carbon-doped boron with and without the addition of nano-SiC. The phase formation during the synthesis as a function of time was followed using powder X-ray diffraction and Rietveld refinement. The superconducting properties were characterized with a magnetometer to investigate doping-induced changes. Mg(B1–x C x )2 is obtained with nano-precipitates and different compositions depending on the synthesis temperature. It is found that the addition of nano-SiC prevents the phase formation at low temperature (700°C). Nevertheless, the best superconducting properties are obtained for the sample treated at 900°C using simultaneously C and SiC, with a critical current density of 105 A cm−2 at 3 T and 20 K, named the 900-20-C-nanoSiC sample.

YBa2Cu3O6+δ (YBC) oxygen deficient perovskite was synthesized by an auto-combustion method and was studied as potential cathode for Intermediate Temperature Solid Oxide Fuel Cell (IT-SOFC). Synchrotron X-ray thermodiffraction in air shows a phase transition from orthorhombic Pmmm to tetragonal P4/mmm space groups at ~ 425 °C. The chemical compatibility with Ce0.9Gd0.1O1.95 (GDC) electrolyte was investigated in air where certain reactivity was observed above 800 °C. However, the main phase is Ba(Ce1-xYx)O3, a good ionic conductor. The catalytic performance in air was obtained by electrochemical impedance spectroscopy (EIS) measurements on YBC/GDC/YBC symmetrical cells. The area specific resistance (ASR) values change from 13.66 to 0.14 Ω cm2 between 500 and 800 °C, with activation energy (Ea) of 0.41 eV. The results suggest potential applications of YBC as IT-SOFC cathode.

In this work, we present the characterization of Ti sheathed MgB $_2$ wires prepared by PIT with two different cross-sections: circular and hexagonal. We determined the crystallographic texture of both the Ti sheath and the MgB $_2$ core by X-ray diffraction (XRD) pole figures. We evaluated the critical current density ( $J_c$ ) of the wires in two different directions using a SQUID magnetometer, in order to determine the anisotropic factor of the current density ( $J_{af}$ ). We found that $J_{af}$ is larger than one and it is field independent for both wires, consistently with the increased probability to encounter the basal planes perpendicular to the axial direction ( $AD$ ) obtained in the crystallographic texture.

Compounds based on barium cerates and zirconates, Ba(Ce,Zr)O3−δ, are oxides able to transport protons through their crystal lattice by proton hopping between oxygen sites. This feature makes them potential candidates as electrolytes for proton conducting solid oxide fuel cells (PC-SOFCs). Pr-doping this family of compounds decreases sintering temperature and introduces electronic conductivity. This work presents a systematic study of the high temperature properties of BaCe0.4Zr0.4Pr0.2O3−δ (BCZP) perovskite in view of its potential application as a PC-SOFC cathode. At room temperature, BCZP presents as a rhombohedral structure, which transforms reversibly to cubic at 550 °C in dry air. Electrical measurements under dry and wet air with water vapor (∼2% H2O) and heavy water vapor (∼2% D2O) were employed to study the conductivity over a wide temperature range. The total conductivity data exhibit behavior changes between 400 and 600 °C which could be associated with a crystal structure transition. BCZP presents low total conductivity (64 μS cm−1 at 600 °C), which limits its application as single phase cathode material. However, the material has good thermomechanical compatibility with electrolytes (∼11 × 10−6 K−1) and high CO2 tolerance (T > 900 °C). These properties suggest that this compound could be used as an oxide support for composite, or backbone for impregnated, electrodes, or as a buffer layer to avoid degradation mechanisms improving the performance of another cathode material.

Zirconia-based ceramics possess a wide range of relevant applications due to its unique mechanical, electrical and optical properties. On the one hand, ZrO2 has a high mechanical and chemical resistance, which is suitable as protective coating. On the other hand, yttria-stabilized zirconia (YSZ) is one of the main electrolyte materials for solid oxide fuel cells (SOFC) devices due to its high ionic conductivity at high temperatures. In this work, ZrO2 and YSZ thin films synthesized by sol-gel method and deposited by dip coating is studied. ZrO2 films are synthesized as coatings for Zircaloy rod spacer grids used for critical heat flux tests, while YSZ films are synthesized for non-electrolyte supported SOFC. Morphological characterization of these films is performed by SEM, while TEM and XRD provide insight on the crystallographic properties. Electrical properties of these materials are measured by conductivity experiments. Highly dense films with good adherence to substrates and thickness above 200 nm are achieved by this method. The nano grain size allows to obtain high symmetry phase stabilization, which enhance the desired properties in both materials for the proposed applications.

The presence of texture in Ti sheathed MgB2 cables, induced by the manufacturing process, have been evaluated using XRD pole figures. Drawn monofilamentary and rolled multifilamentary cables have been compared in order to determine the effect of different deformation degrees arising from the thermo-mechanical treatments. Finally, the critical current density of the cables (Jc) was evaluated using a SQUID magnetometer. We found that MgB2 {10 1 - 0} planes align with the AD direction after drawing, while after rolling, this alignment is not present. The Jc ratio between parallel and perpendicular field is larger for the monofilamentary than for multifilamentary wires, which may be correlated with the differences in the MgB2 texture between these samples.

The optimization of MgB2 superconducting properties is extremely important for practical application. The introduction of an effective artificial pinning center in this material can enhance its critical current density efficiently. In this paper, VB2 is described as a material that provides effective pinning in the MgB2 bulks. The simultaneous addition of SiC as a carbon source is also analyzed. The samples were prepared using ball milling under a controlled atmosphere and heat treatment with a continuous argon flux. As a result, the superconducting properties could be optimized due to the effective improvement in the pinning behavior as well as with the carbon doping. Fil: Da Silva, L.B.S.. Universidade de Sao Paulo; Brasil Fil: Serquis, Adriana Cristina. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Ciudad Universitaria. Unidad Ejecutora Instituto de Nanociencia y Nanotecnologia. Unidad Ejecutora Instituto de Nanociencia y Nanotecnologia - Nodo Bariloche | Comision Nacional de Energia Atomica. Unidad Ejecutora Instituto de Nanociencia y Nanotecnologia. Unidad Ejecutora Instituto de Nanociencia y Nanotecnologia - Nodo Bariloche.; Argentina Fil: Hellstrom, Eric. Florida State University; Estados Unidos Fil: Rodrigues, D.. Universidade de Sao Paulo; Brasil

Oxides with proton conductivity have a great potential for applications in environmental energy technology. Despite the BaCe0.4Zr0.4Y0.2O3−δ (BCZY) perovskites being well-known proton conductors, it is a challenge to determine the optimal operating temperature range where the energy applications benefit most from this unique property. The protonic transport properties strongly depend on crystal structure and local distortions in the participating cation coordination sphere, according to related temperatures and gas feed. The transport and crystallographic properties of BCZY were simultaneously studied by impedance spectroscopy (IS) and synchrotron X-ray diffraction (S-XRD). A strong correlation between conductivity and the lattice parameter, corresponding in principle to a cubic symmetry, was observed, mainly between 400 and 700 °C. The protonic conductivity range was analyzed by the H/D isotopic effect on the impedance spectra, which helped to identify protonic conduction as the governing transport mechanism below 600 °C, while the transport via oxygen vacancies dominates above this temperature. In order to assess the real crystallographic structure, the simultaneous refinement of laboratory XRD and neutron diffraction (ND) patterns was performed. According to this, BCZY changes from rhombohedral symmetry below 400 °C to cubic at 600 °C in a second-order phase transition. Complementary quasielastic neutron scattering (QENS) enables us to determine a protonic jump length of 3.1 Å, which matches the O–O distances in the octahedral oxygen coordination sphere around the cations. These results support the protonic self-diffusion through proton hopping between intraoctahedral O sites as the main transport mechanism up to 600 °C., This work was supported by Agencia Nacional de Promocion de Ciencia y Tecnologia (ANPCyT) PICT-2016-2965 and PICT2014-1849, CONICET PIP-2015-0565, LNLS (Brazil), under proposals 20150099 and 20170278, and ILL (France) under proposal 7-03-168. L. Giebeler is grateful to the German Federal Ministry of Education and Research (BMBF) and the Argentinian Ministry of Science and Technology (MinCyT) for funding in the bilateral project DeFLeST (01DN14002). J. A. Alonso thanks the Spanish Ministry for Science, Innovation and Universities for funding the Project MAT2017-84496-R.

In this work, the characterization of ZrO2 thin films synthesized by the sol-gel method, using two different routes, is presented. Thin films were deposited by dip-coating on glass and Zircaloy-4 (Zry-4) substrates, and heat treated at 500 °C under atmospheric air. Characterization was carried out using X-Ray Diffraction (XRD), Grazing Incidence X-Ray Diffraction (GIXRD), High Temperature X-Ray Diffraction (HT-XRD), Raman Spectroscopy (RS), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). Electrical properties of films were studied by conductivity measurements. These films present a thickness of 90 and 200 nm on glass, depending on the synthesis route, and consist of nanocrystals with predominantly tetragonal phase. On coated Zry-4, a non-uniform but dense ZrO2 layer without cracks grows, in contrast with the un-coated Zry-4, where a thicker layer was formed with the presence of micro-fissures. A GIXRD study showed that both tetragonal and monoclinic phases are present in the oxide layer. Conductivity measurements indicated that these films have excellent insulating properties, with resistivity values that exceed 0.5 M Ω.cm below 300 °C. These exceptional properties and the retention of high symmetry phases make this method very attractive for growing good electrical insulator and anti-corrosion ZrO2 thin film coatings.

The modification of surface composition after long-term operation is one of the most reported degradation mechanisms of (La,Sr)(Co,Fe)O3-δ (LSCFO) cathodes for Solid Oxide Fuel Cells (SOFCs). Nevertheless, its effect on the oxygen reduction reaction kinetics of porous LSCFO cathodes has not been yet reliably established. In this work, La- and Sr-enrichment at the LSCFO surface of porous cathodes has been induced after 50 h aging at 800 °C under air. Such cation redistribution can extend up to ∼400 nm depth under the LSCFO surface as detected by high resolution Scanning Transmission Electron Microscopy-Energy Dispersive Spectroscopy maps acquired inside the cathode pores. The observed surface chemical changes hamper the oxygen surface exchange reaction at the LSCFO/gas interface. Accordingly, a suitable Electrochemical Impedance Spectroscopy analysis revealed that the oxygen ion conductivity remains practically unaltered during the aging treatment while the oxygen surface exchange resistance increases up to 1.8 times. As a result, the cathode impedance response deteriorates within the 10–0.1 Hz frequency range during the aging treatment, resulting in a total cathode area specific resistance increase of 150%. The methodology adopted has demonstrated to be very valuable for studying the degradation of SOFC cathodes produced by the modification of surface composition.

In this work, we have studied La0.4Sr0.6Co0.8Fe0.2O3-δ/Ce0.8Gd0.2O2-δ/La0.4Sr0.6Co0.8Fe0.2O3-δ symmetrical cells containing Ce0.8Gd0.2O2-δ electrolytes synthetized with and without the addition of cobalt as sintering aid. Electrochemical impedance spectroscopy results indicate that both electrolyte and cathode impedance response are affected by the addition of Co to the electrolyte, despite using cathodes with similar nano/microstructure according to scanning electron microscopy observations. Transmission electron microscopy characterization revealed the formation of columnar structures at the cathode/electrolyte interface of the cell with Co-doped electrolyte. These columnar structures would negatively affect the cell performance hindering the diffusion of oxide ions from the cathode to the electrolyte.

Daniela Castro es Secretaria de Investigación, Política Industrial y Producción para la Defensa. Ana Franchi es presidenta del Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET). Mirta Iriondo preside la Fábrica Argentina de Aviones (FAdeA). Celeste Saulo es directora del Servicio Meteorológico Nacional (SMN). Adriana Serquises presidenta de la Comisión Nacional de Energía Atómica (CNEA).

Nanocrystalline La0.6Sr0.4Fe0.8Cu0.2O3-δ (LSFCu) material was synthetized by combustion method using EDTA as fuel/chelating agent and NH4NO3 as combustion promoter. Structural characterization using thermodiffraction data allowed to determine a reversible phase transition at 425 °C from a low temperature R-3c phase to a high temperature Pm-3m phase and to calculate the thermal expansion coefficient (TEC) of both phases. Important characteristics for cathode application as electronic conductivity and chemical compatibility with Ce0.9Gd0.1O2-δ (CGO) electrolyte were evaluated. LSFCu presented a p-type conductor behavior with maximum conductivity of 135 S cm-1 at 275 °C and showed a good stability with CGO electrolyte at high temperatures. This work confirmed that as prepared LSFCu has excellent microstructural characteristics and an electrical conductivity between 100 and 60 S cm-1 in the 500-700 °C range which is sufficiently high to work as intermediate temperature Solid Oxide Fuel Cells (IT-SOFCs) cathode. However a change in the thermal expansion coefficient consistent with a small oxygen loss process may affect the electrode-electrolyte interface during fabrication and operation of a SOFC. Fil: Vázquez, Santiago. Universidad de la República; Uruguay Fil: Davyt, Sebastián. Universidad de la República; Uruguay Fil: Basbus, Juan Felipe. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina Fil: Soldati, Analía Leticia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina Fil: Amaya, Alejandro. Universidad de la República; Uruguay Fil: Serquis, Adriana Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina Fil: Faccio, Ricardo. Universidad de la República; Uruguay Fil: Suescun, Leopoldo. Universidad de la República; Uruguay

In this work we studied the electrochemical performance of Ba0.5Sr0.5Fe0.8Cu0.2O3-δ (BSFCu) as cathode for Intermediate Temperature Solid Oxide Fuel Cells (IT-SOFC) with Ce0.9Gd0.1O1.95 (CGO) electrolyte and the effect of the symmetric cell preparation temperature on the oxygen reduction reaction (ORR) activity. Symmetrical cells with the configuration BSFCu/CGO/BSFCu were prepared at 900 °C, 950 °C and 1000 °C to perform the electrochemical characterization in the 500-700 °C temperature range. The resultant area specific resistance (ASR) of the cells with different preparation temperatures followed the tendency: ASR900°C < ASR950°C < ASR1000°C. The symmetric cell constructed at 900 °C showed ASR values of 0.18, 0.078 and 0.035 Ω cm2 at 600, 650 and 700 °C respectively, which demonstrated superior electrochemical activities than previous reports. Additional, X-ray diffraction (XRD), scanning and transmission electron microscopies (SEM and TEM) techniques were used to characterize the microstructure of the original and fired BSFCu materials and correlate it with the cell preparation temperature. Fil: Vázquez, Santiago. Universidad de la Republica. Facultad de Química; Uruguay Fil: Basbus, Juan Felipe. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Gerencia de Área de Aplicaciones de la Tecnología Nuclear. Gerencia de Investigación Aplicada; Argentina Fil: Soldati, Analía Leticia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Gerencia de Área de Aplicaciones de la Tecnología Nuclear. Gerencia de Investigación Aplicada; Argentina Fil: Napolitano, Federico Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Gerencia de Área de Aplicaciones de la Tecnología Nuclear. Gerencia de Investigación Aplicada; Argentina Fil: Serquis, Adriana Cristina. Comisión Nacional de Energía Atómica. Gerencia de Área de Aplicaciones de la Tecnología Nuclear. Gerencia de Investigación Aplicada; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Suescun, Leopoldo. Universidad de la Republica. Facultad de Química; Uruguay

MgB $$_{2}$$ has become a commercially attractive material for technological applications for its particular superconducting properties. However, due to its brittleness to obtain wires, a metallic sheath is needed for drawing. In the present work, grade 2 titanium has been used as sheath material, and several multifilamentary wires have been prepared. The powder-in-tube method has been used to prepare the wires with the in situ variant, where the sheath is filled with the unreacted precursor powders (Mg and B). Different thermal treatments have been investigated including several intermediate treatments during the drawing process in addition to the final one. This last treatment is necessary to accomplish the synthesis and heal the cracks generated during the cold work. The superconducting properties were determined by magnetization measurements on a SQUID magnetometer, and the microstructure evolution was followed by TEM and SEM microscopy. Mechanical behavior is also evaluated.

The Focused Ion Beam (FIB) technique was used to prepare site-specific samples from interfacial regions of different solid oxide fuel cells assemblies. Transmission and Scanning Electron Microscopy on the FIB foils combined with Electrochemical Impedance Spectroscopy (EIS) allowed the characterization of the electrode/electrolyte interphases and the determination of its influence on the cell performance after long-term operation conditions. This work reviews two cases: on one hand, Ln2NiO4+d (Ln= La, Nd) cathodes deposited on both Y0.08Zr0.92O1.96 and Ce0.9Gd0.1O1.95 electrolytes, that react at 900 °C during the adhesion treatment and at temperatures higher than 650 °C during the EIS measurements. These samples present a reaction layer of 10 nm thickness, which contains elements of both phases and was found responsible of the cell performance degradation. On the other hand, La0.4Sr0.6Co0.8Fe0.2O3-δ cathodes showed excelent performance on Ceria electrolytes, even after 1 000 h at operation conditions. In that case, the microscopic analyses of FIB foils showed a semi-coherent interphase growth. Fil: Soldati, Analía Leticia. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Montenegro Hernandez, Alejandra. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Baque, Laura Cecilia. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Troiani, Horacio Esteban. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Mogni, Liliana Verónica. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Schreiber, Anja. Helmholtz-Zentrum Potsdam; Alemania Fil: Serquis, Adriana Cristina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Solid oxide fuel cell performance is usually limited by high cathodic area specific resistance (ASR) at intermediate temperatures (500-700°C). ASR can be decreased by reducing particle size to nanometer range. This improvement is usually ascribed to the area/volume ratio increase and a higher concentration of active sites for the oxygen reduction reaction (ORR). Nevertheless, this solely explanation seems not to be enough for explaining the high electrochemical performance of some nanostructured La0.4Sr0.6Co0.8Fe0.2O3-d cathodes previously reported (Baqué et al., Electrochemistry Comm. 10 (2008) 1905-1908). Accordingly, the ORR of these cathodes was studied by electrochemical impedance spectroscopy (EIS) under air and under pure oxygen within the 400-700°C range. The nanostructure was characterized even at atomic level by transmission electron microscopy (TEM), revealing that the cathode is composed of nanocrystals surrounded by zones with some degree of crystalline disorder. These results suggest that this kind of nanostructure facilitate the ORR in this compound. Fil: Baque, Laura Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Area de Investigación y Aplicaciones No Nucleares. Gerencia de Física (Centro Atómico Bariloche); Argentina. Technical University Of Denmark; Dinamarca Fil: Soldati, Analía Leticia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Area de Investigación y Aplicaciones No Nucleares. Gerencia de Física (Centro Atómico Bariloche); Argentina Fil: Troiani, Horacio Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Area de Investigación y Aplicaciones No Nucleares. Gerencia de Física (Centro Atómico Bariloche); Argentina Fil: Schreiber, Anja. Helmholtz Gemeinschaft; Alemania Fil: Caneiro, Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Area de Investigación y Aplicaciones No Nucleares. Gerencia de Física (Centro Atómico Bariloche); Argentina Fil: Serquis, Adriana Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Gerencia del Area de Investigación y Aplicaciones No Nucleares. Gerencia de Física (Centro Atómico Bariloche); Argentina

In this work, a combined synchrotron X-ray diffraction (XPD), X-ray absorption near edge spectroscopy (XANES) and Extended X-ray Absorption Fine Structure (EXAFS) study of La0.4Sr0.6Ti1-yCoyO3±δ (0 ≤ y ≤ 0.5), intended as symmetric solid oxide fuel cells electrode, is presented. Charge compensation mechanisms were characterized by room temperature measurements; LSTC has a perovskite pseudocubic structure with an A-site vacancy concentration related with Co doping level. This result seems to be triggered by the fact that Ti remains in a higher formal valence (around 4+) independent of the Co concentrations. On the contrary, Co K-edge XANES spectra show a dependency with the doping level but this seems to be related to structural changes. In-situ measurements simulating a symmetric SOFC working environment show that LSTC undergoes a rhombohedral to cubic perovskite phase transition with critical temperature dependent of the structural distortion level. Fil: Napolitano, Federico Ricardo. Comisión Nacional de Energía Atómica. Gerencia de Area de Aplicaciones de la Tecnología Nuclear. Gerencia de Investigación Aplicada; Argentina Fil: Soldati, Analía Leticia. Comisión Nacional de Energía Atómica. Gerencia de Area de Aplicaciones de la Tecnología Nuclear. Gerencia de Investigación Aplicada; Argentina Fil: Geck, Jochen. Leibniz Institute for Solid State and Materials Research IFW; Alemania Fil: Suescun, Leopoldo. Universidad de la Republica. Facultad de Química; Uruguay Fil: Acuña, Leandro Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Científicas y Técnicas de las Fuerzas Armadas. Centro de Investigaciones en Sólidos; Argentina Fil: Fernandez Zuvich, Afra. Comisión Nacional de Energía Atómica. Gerencia de Area de Aplicaciones de la Tecnología Nuclear. Gerencia de Investigación Aplicada; Argentina Fil: Lamas, Diego German. Universidad Nacional del Comahue. Facultad de Ingeniería; Argentina Fil: Serquis, Adriana Cristina. Comisión Nacional de Energía Atómica. Gerencia de Area de Aplicaciones de la Tecnología Nuclear. Gerencia de Investigación Aplicada; Argentina

We present combined Synchrotron X-ray Absorption Near Edge Spectroscopy (XANES) andExtended X-ray Absorption Fine Structure (EXAFS) study of La0.4Sr0.6Ti1yCoyO3d(0 The measurements were performed at room temperature at the Ti and the Co K-edges inorder to determine the local structural and electronic changes around the two transitionmetals. We find that Ti remains in a higher formal valence (around 4þ) independent of theCo concentration. In contrast to this, dramatic and systematic changes are observed for theCo as a function of y.We conclude that the stability of the Ti4þ triggers the A-site deficiencyin our samples and predicts that oxygen vacancies are much more easily formed at largeCo content, which in turn will greatly enhance the performance as electrode material. Fil: Napolitano, Federico Ricardo. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina Fil: Soldati, Analía Leticia. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina Fil: Geck, Jochen. Leibinz. Institute for Solid State and Materials Research; Alemania Fil: Lamas, Diego German. Universidad Nacional del Comahue; Argentina Fil: Serquis, Adriana Cristina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina

We present a crystallographic, morphologic and redox dynamic study on (60:40) NiO/Ce0.9Gd0.1O1.95 (NiO/GDC) cermets simulating Intermediate Temperature Solid Oxide Fuel Cells (IT-SOFC) anodes in situ conditions. We tested micro- and nanometer sized materials at 700ºC in three different atmospheres (5% H2, 5% O2 and 20% CH4). We used Dispersive X-ray Absorption Spectroscopy (DXAS) analysisat the Ce L3-edge and at the Ni K-edge to follow the metal´s oxidation states. A correlation between the catalytic/redox properties and the sample´s characteristics (microstructure, Ni distribution, etc.) was found, indicating that nanometric sized particles showed faster and higher reduction extents than micrometric particles of the same composition. Fil: Fernandez Zuvich, Afra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina Fil: Larrondo, Susana Adelina. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; Argentina. Universidad de Buenos Aires. Facultad de Ingeniería. Departamento de Ingeniería Química. Laboratorio de Procesos Catalíticos; Argentina Fil: Saleta, Martin. Laboratório Nacional de Luz Síncrotron; Brasil Fil: Napolitano, Federico Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina Fil: Caneiro, Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina Fil: Troiani, Horacio Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina Fil: Lamas, Diego Germán. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Arce, Mauricio Damián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina Fil: Serquis, Adriana Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina Fil: Soldati, Analía Leticia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina

One of the remaining challenges for the solid oxide fuel cell (SOFC) technology is decreasing its operation temperature to the 500-800 °C range in a cost-effective way without diminishing the cell performance. In this work, we studied a symmetrical cell composed of Sr0.6La0.4Co0.8Fe0.2O3-δ (LSCFO) cathodes deposited on a Ce0.8Y0.2O2-δ (CYO) substrate by the simple, cost-effective and scalable spin coating technique. The nanostructured cathode is composed of agglomerated ∼100-200 nm particles with ∼50 nm crystallite size. Electrochemical impedance spectroscopy (EIS) analysis indicates that electrolyte grain boundary conductivity strongly depends on the cathode nature. The detailed high resolution transmission electron microscopy (HR-TEM) characterization of the LSCFO/CYO interface reveals that the LSCFO cathode is well adhered to the CYO electrolyte. The improved nano/microstructure of the cathodes and the cathode/electrolyte interface yields to cathode area specific resistance (ASR) values as low as 0.4 Ωcm2 at 550 °C, being these values even lower than those previously reported in literature for cathodes in optimized LSCFO/CYO/YSZ/CYO/LSCFO cells. Fil: Baque, Laura Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina Fil: Padmasree, K.P.. Centro de Investigación y de Estudios Avanzados; México Fil: Ceniceros Reyes, M.A.. Centro de Investigación en Química Aplicada; México Fil: Troiani, Horacio Esteban. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina Fil: Serquis, Adriana Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina Fil: Soldati, Analía Leticia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina

Lanthanum strontium titanates based oxides, materials with perovskite-type crystal structure, are good candidates for symmetrical fuel cell electrodes. They can become good mixed conductors (electronic and ionic) and reach adequate electrocatalytic activity for both oxygen reduction and fuel oxidation reactions if the right doping or structural modification of the (La,Sr)TiO3 compound is performed. However, the crystallographic information reported in the literature indicates a noticeable lack of reproducibility, since it is strongly dependent on synthesis conditions. In this work, La0.4Sr0.6Ti1−yCoyO3+δ (0.0 ≤ y ≤ 0.5) synthesis by a low-temperature chemical route and its structural characterization by X-ray powder diffraction and transmission electron microscopy are reported. From Rietveld refinements results, charge compensation mechanisms are studied and their correlation with synthesis parameters is discussed. We show that the creation of Sr vacancies at the A-site of the perovskite-type structure is the main compensation mechanism and their concentration decreases with the incorporation of Co in the crystal structure.

The discovery of superconductivity at 39 K in MgB2 has been catching the attention of scientists due to the possibility of applying the material in magnets and electronic devices operating with cryocoolers (temperatures around 20 K). In the present work, a methodology to optimize the critical current densities of this material is described. MgB2 bulk samples were prepared and analyzed with the addition of other diborides with the same C32 hexagonal structure as MgB2 (TaB2 , ZrB2 , VB2 , and AlB2 ) and with simultaneous addition of SiC. Microstructural characterization, performed using SEM+EDS and XRD, was extremely important to determine the distribution and compositional characterization of the superconducting phase. Magnetic superconducting characterization using SQUID was performed to determine the best material addition. As a result we could analyze the behavior of each addition on the current transport capacity, including an analysis of the magnetic flux pinning mechanisms.

We studied the electrochemical performance and microstructural characteristics of La0.5Sr0.5CoO3-d (LSCO) cathodes prepared by pulse laser deposition (PLD). This technique allows the growth of nanostructured cathode layers with vertically-aligned nanopores (VANP). In some samples, a vertically aligned nanocomposite (VAN) LSCO/CGO layer was introduced between the cathode and the Ce0.9Gd0.1O1.95 (CGO) electrolyte. The structure and morphology of several film configurations were characterized by X-ray diffraction, transmission and scanning electron microscopy, and synchrotron X-ray reflectometry, while the electrochemical properties were evaluated by means of impedance spectroscopy. We found that cathode area specific resistances (ASR) for VANP LSCO samples are almost independent of film thickness and are within the lowest reported values. A significant decrease in the ASR values was observed while heating the sample, but after this first heating, the ASR values were reproducible, indicating that these nanostructures are stable in the used temperatures and oxygen partial pressure ranges.

In this work we successfully applied a FIB/lift-out technique to prepare site-specific thin samples containing the cathode/electrolyte interface between two La0.4Sr0.6Co0.8Fe0.2O3-δ (LSCF) / Ce0.9Gd0.1O2-δ (CGO) half cells. Despite different cathode thickness (15 μm and a 5 μm), both samples presented similar composition and nanostructure. However, an exhaustive microscopic analysis by SEM and TEM at high resolution modes, revealed that: the 15 μm sample presented a perfectly attached interface, while the other showed pores at the interfacial boundary, decreasing the real LSCF/CGO contact. In this way we could explain part of the difference in area specific resistance between measured between them.

A thin layer of a vertically aligned nanocomposite (VAN) structure is deposited between the electrolyte, Ce0.9Gd0.1O1.95 (CGO), and the thin-film cathode layer, La0.5Sr0.5CoO3 (LSCO), of a thin-film solid-oxide fuel cell (TFSOFC). The self-assembled VAN nanostructure contains highly ordered alternating vertical columns of CGO and LSCO formed through a one-step thin-film deposition process that uses pulsed laser deposition. The VAN structure significantly improves the overall performance of the TFSOFC by increasing the interfacial area between the electrolyte and cathode. Low cathode polarization resistances of 9 × 10−4 and 2.39 Ω were measured for the cells with the VAN interlayer at 600 and 400 °C, respectively. Furthermore, anode-supported single cells with LSCO/CGO VAN interlayer demonstrate maximum power densities of 329, 546, 718, and 812 mW cm−2 at 550, 600, 650, and 700 °C, respectively, with an open-circuit voltage (OCV) of 1.13 V at 550 °C. The cells with the interlayer triple the overall power output at 650 °C compared to that achieved with the cells without an interlayer. The binary VAN interlayer could also act as a transition layer that improves adhesion and relieves both thermal stress and lattice strain between the cathode and the electrolyte.

In this work, the electrochemical performance of La0.4Sr0.6Co0.8Fe0.2O3 (LSCF) cathodes was studied for different morphologies. LSCF powders have been prepared by three different methods: an acetic acid-based chemical route, an hexamethylenetetramine (HTMA) chemical route and spray pyrolysis. The cathode films were fabricated by spin coating inks, starting from these powders, onto Ce0.9Gd0.1O1.95 ceramic substrates. We found that nanostructured LSCF samples can be obtained by all methods, but with different morphologies. In particular, spray pyrolysis method allows the attainment of LSCF cathode films with an atypical microstructure (i.e. spherical particle shape, nanometric grain sizes and large and open porosity). We show that the electrochemical properties of LSCF cathodes films strongly depend on microstructure and morphology and cathode polarization resistance can decrease considerably if optimized synthesis parameters are used.

In this work we describe the effects of adding different amount of single-wall (sw) carbon nanotubes (CNT) on the superconducting properties of MgB 2. We observed that the amount of swCNT that partially dilute into the MgB 2 matrix is lower than for double-wall (dw) CNT samples for the same nominal content. This C incorporation leads to an increase of the upper critical field (Hc2), with a maximum Hc2(0) extrapolated value of 33.5 T, expected for a two-gap superconductor in the dirty limit. At the same time, the fraction of swCNT that has not been incorporated into MgB 2 lattice may retain their structural integrity acting as strong vortex pinning centers. In this case the optimum nominal swCNT content for increasing critical current density (Jc) is in the range 7.5-10%at.

Starting from commercial MgB2 325 mesh powder, we further reduced the agglomerates by attrition milling in nitrogen atmosphere to minimize oxidation. The milling time was varied between 10 and 40 hours, using two different types of milling media: yttria stabilized zirconia and CW balls. We studied the influence of milling time and milling media on the broadening of x-ray diffraction peaks and the superconducting properties of the powders. A highly energetic milling markedly decreased the crystallite size but damaged the superconducting properties. We observed a decrease of the Tc, consistent with the observed crystallinity loss. We prepared tapes with the 40-hours-milled powders and analyzed the resulting microstructures when using a soft (silver) and a hard (stainless steel) metal sheath, heat treated for 1 hour at 615degC in argon. This temperature was chosen after observing the existing reactions between magnesium diboride and silver by DTA analysis of the powders, so as to minimize the reaction at the superconductor-silver interface. We characterized the superconducting properties by determining the magnetic Jc in a SQUID. We performed 4-point bending micro-tests on the tapes to evaluate their mechanical strength.

The electrochemical performance of La0.4Sr0.6Co0.8Fe0.2O3−δ (LSCF) cathodes with different nano/microstructures is compared using the area specific resistance (ASR). Cathodes are prepared using two chemical routes, including a novel method to obtain nanosized LSCF oxide. The results clearly point that the intermediate temperature solid oxide fuel cells (IT-SOFC) cathode performance strongly depends on microstructure and that ASR can vary more than two orders of magnitude for identical composition and different morphologies, reaching values as low as 0.05 Ω cm2 at 600 °C and 0.4 Ω cm2 at 450 °C using the novel chemical route, which are even lower than the best known cathodes for IT-SOFC. Keywords: Solid oxide fuel cell, Cathode materials, Mixed conductor, Polymeric solution

By applying a combination of characterisation tools, changes in structural and superconducting properties with nominal Mg non-stoichiometry in MgxB2 are found. The non-stoichiometry produces enhanced in-field critical current densities (Jc’s) and upper critical field / irreversibility field (Hc2/Hirr(T)) values. Upper critical fields of ∼ 21 T (4.2 K) were obtained in nominal Mg-deficient samples compared to ∼ 17 T (4.2 K) for near-stoichiometric samples.

Nanostructured cathode thin films with vertically-aligned nanopores (VANP) were processed using a pulsed laser deposition technique (PLD). These VANP structures enhance the oxygen-gas phase diffusivity, thus improve the overall thin film SOFC performance. La 0.5 Sr 0.5 CoO 3 (LSCO) and La 0.4 Sr 0.6 Co 0.8 Fe 0.2 O 3 (LSCFO) were deposited on various substrates (YSZ, Si and pressed Ce 0.9 Gd 0.1 O 1.95 disks). Microstructures and properties of the nanostructured cathodes were characterized by TEM, HRTEM, SEM and electrochemical measurements. Additionally these well-aligned VANP structures relieve or partially relieve the internal thermal stress and lattice strain caused by the differences of thermal expansion coefficients and lattice mismatch between the electrode and the electrolyte.

The dip-coating method has been successfully used for depositing porous electrodes of La 0.4 Sr 0.6 Co 0.8 Fe 0.2 O 3– δ (LSCF) films. Perovskite oxide cobaltites powders have been prepared by an acetic acid-based gel route. Then, cathode films were deposited onto ceramic substrates of the usual electrolyte Cerium Gadolinium Oxide (CGO) by dip coating. The structure and morphology of the powders and films were characterized by X-ray, diffraction (XRD) and scanning electron microscopy (SEM) respectively, to study the correlation between microstructure and deposition parameters. Optimum parameters for obtaining continuous, homogeneous and crack free LSCF films were determined.

We present a detailed analysis of the effect of the sheath materials on the microstructure, and superconducting properties of MgB2 wires produced by the powder-in-tube method (PIT). We reduced commercial MgB2 powder by attrition milling in nitrogen atmosphere using tungsten carbide balls and obtained powders with grain sizes lower than 150 nm and different strains states through this process. Several Ti, Sstainless steel and copper monofilamentary wires were prepared using these powders by the PIT method. We investigated different thermal treatments and mechanical paths during the processing of the wires for the enhancement of the critical currents. The superconducting properties were determined by magnetization measurements in a SQUID magnetometer. The correlation between the thermal treatments, structure and superconducting properties is discussed. Fil: Sobrero, Cesar Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina Fil: Malachevsky, Maria Teresa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina Fil: Serquis, Adriana Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Bariloche; Argentina

An important example of oxide materials exhibiting oxygen non-stoichiometry are the high temperature superconductors (HTSC). In this family of materials the variation of the oxygen content modifies the defect structure and the carrier concentration, causing phase transitions and structural distortions with the consequent change in their physical properties. In some systems, a continuous variation of the physical properties as a function of the oxygen content is observed, while in others, small changes of the oxygen content strongly modify the superconducting behavior of these materials. In this paper, we review an analysis of the influence of the oxygen content on the physical properties of three HTSC materials: the electron doped Nd–Ce–Cu–O superconductor, the R–Ba–Cu–O (R=Nd, Gd, Pr) 123 compounds and the (Hg, Re)-1201 material.

The angular-dependent critical current density J/sub c/ in YBa/sub 2/Cu/sub 3/O/sub 7/ films grown by pulsed laser deposition exhibit a sharp peak for magnetic field orientations near the ab plane, which arises from the combined effects of intrinsic pinning and extended defects parallel to the planes. An analysis of the temperature and field dependence of the height and width of this peak allows us to distinguish both contributions. We find that, in a film on single crystal substrate, the peak at low fields is due primarily to the extended defects, but at high fields it is dominated by intrinsic pinning. We compare these results with those of coated conductors with a larger density of ab-oriented correlated defects. We show a novel effect consisting in an inverse correlation between J/sub c/ and the power law exponent (N) of the I-V curves that only occurs in the intrinsic-pinning dominated regime, and we present an interpretation of its origin.

We present an analysis of the effect of SiC doping and heat treatments, including hot isostatic pressing (HIPing), on the microstructure, magnetization and transport properties of MgB/sub 2/ wires and coils prepared by the powder in tube (PIT) method. The HIPed wires have higher critical current densities (J/sub c/) than the annealed wires, especially at high temperatures and magnetic fields, and higher irreversibility field. The improvements are due to the reduction of porosity and to a high density of structural defects, which are the likely source of vortex pinning. We demonstrate that the high-quality properties mentioned above can be retained in longer wires. At 25 K our champion 6-layer coil, made with 25 meters of wire, was able to generate a field of 1 T at self-field. We were able to achieve even higher J/sub c/'s in another coil by combining the addition of SiC and HIPing. We also observed a larger upper critical field due to the SiC doping, which drives the sample to the dirty limit.

We present a study of the sharp peak that develops near the ab -plane orientation in the angular dependent critical current of YBa 2 Cu 3 O 7 (YBCO) films. This peak arises from correlated pinning associated to intrinsic pinning by the layered structure of the YBCO, and from extended planar defects. We measure films produced by pulsed laser deposition (PLD) and metal organic deposition (MOD) on ion beam assisted deposition––MgO, and by PLD on single crystalline substrates. We show that the width and height of the peak increases with the out-of-plane mosaic spread of the films. We discuss the implications of the different structures (columnar and laminar respectively) of the PLD and MOD films.

Two sets of MgB2 samples doped with up to 5 at. % of Al were prepared in different laboratories using different procedures. Decreases in the a and c lattice parameters were observed with Al doping confirming Al substitution onto the Mg site. The critical temperature (Tc) remained largely unchanged with Al doping. For 1 - 2.5 at.% doping, at 20K the in-field critical current densities (Jc's) were enhanced, particularly at lower fields. At 5K, in-field Jc was markedly improved, e.g. at 5T Jc was enhanced by a factor of 20 for a doping level of 1 at.% Al. The improved Jcs correlate with increased sample resistivity indicative of an increase in the upper critical field, Hc2, through alloying., 17 pages, 4 figures, to be published in Superconductor Science and Technology

MgB2 samples synthesized by solid-state reaction were found to contain several types of crystalline defects, including Mg deficiency, coherent precipitates, screw dislocations, and oxygen impurity, depending on the synthesis conditions. The Mg deficiency introduced significant strain in the crystalline lattice of MgB2. A high density of screw dislocations lying on (0001) planes with a Burgers vector of partially relieved the lattice strain. The remnant strain in the MgB2 lattice directly determines the critical superconducting temperature, which decreases with strain. A small amount of oxygen dissolved in the MgB2 matrix is not responsible for lowering Tc observed in our samples.

The microstructures of MgB2 wires prepared by the powder-in-tube technique and subsequent hot isostatic pressing were investigated using transmission electron microscopy. Large amount of crystalline defects including small angle twisting, tilting, and bending boundaries, in which high densities of dislocations reside, were found forming sub-grains within MgB2 grains. It is believed that these defects resulted from particle deformation during the hot isostatic pressing process and are effective flux pinning centers that contribute to the high critical current densities of the wires at high temperatures and at high fields., 16 pages, 6 figures

MgB/sub 2/ wires were produced by the powder-in-tube method, using commercial MgB/sub 2/ powder with 5%at Mg powder added as an additional source of magnesium, and stainless steel as sheath material. Depending on the parameters of the heat treatments, the dc transport critical current can be increased or decreased by more than one order of magnitude as compared with the as-drawn wire. Analysis of the zero-field-cooling dc magnetization demonstrates that these large variations are due to changes in the connectivity of the wires. We discuss the optimization of the annealing conditions in terms of the changes in the microstructure, as determined from TEM and SEM analysis. We show that annealing can strongly improve the connectivity by eliminating most of the micro-cracks present in the un-annealed wires. In contrast, inappropriate annealing conditions result in a deterioration of the connectivity due to the loss of Mg.

We have used a resonant ultrasound spectroscopy technique to measure the bulk and shear modulus of fully dense, polycrystalline MgB2 between 4 and 300 K. Both moduli show good agreement with published first principle calculations. The internal friction shows a broad maximum around 40 K.

We investigated the growth of multi-wall carbon nanotubes (CNTs) catalyzed by SiO2-supported Co–Mo bi-metallic catalyst in flowing CO at 700 °C. We found that both Co and Mo are present in catalytic particles at the tips of CNTs, but their compositions vary from one catalytic particle to another and significantly deviate from the initial mixing composition. The Co concentration and distribution in the catalytic particle of a CNT largely determines the length of the CNT. The CNT growth process is carbon adsorption on exposed area of a catalytic particle and subsequent precipitation at the CNT-catalyst interface or open CNT wall edges. The encapsulation of a catalytic particle was found to occur by the growth of the open-edged graphene walls around the particle. Two types of long CNTs were observed: one with their CNT walls ended at the CNT-particle interface, and the other with their CNT walls open to the environment. The former have diameters similar to their catalytic particle size while the latter have larger diameters.

The Argentinian Association of Crystallography (AACr) is dedicated to promote crystallography all over the country, as well as to bring together groups working in this area of knowledge or employing it as a tool in their research projects. The variety of topics covered by the AACr is wide, in a similar way as in the IUCr. Although crystallography in Argentina dates back to the ´40s, the AACr was founded as a formal scientific association in 2004, on the occasion of the "National Workshop on Crystallography" held in the town of Villa Giardino, Province of Córdoba. The regular annual activities of the AACr include a scientific meeting (3 days), a school on crystallography (1 week) and a workshop (1 day). This year, these activities will be held in the city of Bahía Blanca at the end of October. Considering the importance of crystallography and the need for more dissemination to the general public and students, the AACr decided to organize several educational and outreach activities in Argentina, taking into advantage the great enthusiasm generated by the IYCr 2014. The following list summarizes the ongoing activities at the AACr: 1) Organization of a National Crystal Growing Contest for High School Students, which is nowadays on its fourth successful edition (see poster by Florencia Di Salvo et al.). This Contest also includes a series of crystallography workshops for teachers all around the country given by AACr researchers, 2) Talks and live experiments at the Tecnópolis Science Fair (see picture) and at the Buenos Aires International Book Fair, 3) Exhibitions and talks at the Scientific Cultural Center of the Argentinian Ministry of Science, 4) Exhibition at the Fair of Science and Technology ?Science Square? of the Matanza County in Buenos Aires, 5) Organization of the Workshop: ?From Atoms to Crystals: Workshop of Crystallography and Crystal Growing? aimed for primary school teachers in the city of Bariloche (see poster by Adriana Serquis et al.), and 6) Participation in the ?Buenos Aires Museum Night? with a structural biology stand showing protein crystals and three-dimensional protein structures obtained by X-ray diffraction. Many of these actions, launched with the same spirit of the IYCr 2014, have now become regular activities in our Association. The AACr would like to thank all our members, especially Vanesa Contini and Vanina Franco, for her help. Fil: Klinke, Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; Argentina Fil: Di Salvo, Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina Fil: Freire Espeleta, Eleonora. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; Argentina Fil: Fuertes, Valeria Cintia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Universidad Nacional de Córdoba; Argentina Fil: Narda, Griselda Edith. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis; Argentina. Universidad Nacional de San Luis; Argentina Fil: Polla, Griselda Ines. Comisión Nacional de Energía Atómica; Argentina Fil: Rodriguez, Maricel Gabriela. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina Fil: Serquis, Adriana Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; Argentina Fil: Suarez, Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina Fil: Lamas, Diego Germán. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Martín; Argentina