Encoding Magnetic States in Monopole-Like Configurations Using Superconducting Dots

Palau Masoliver, Anna et al.A large manifold of nontrivial spin textures, including the stabilization of monopole-like fields, are generated by using a completely new and versatile approach based on the combination of superconductivity and magnetism. Robust, stable, and easily controllable complex spin structures are encoded, modified, and annihilated in a continuous magnetic thin film by defining a variety of magnetic states in superconducting dots.This work has been supported by MINECO (MAT2014-51778-C2-1R, MAT2012-35370, CSD2007-0041), Generalitat de Catalunya (2014- SGR-00753, 2014-SGR-150, 2014-PROD00059), European Seventh Framework Program (FP7/2007-2013) under grant agreement 312284, EU-NMP-LA-2012-280432EUROTAPES project and Cost Action MP1201. A. Sanchez acknowledges a grant from ICREA Academia, funded by the Generalitat de Catalunya. ICMAB acknowledge the Severo Ochoa Center of Excellence mentioned from MINECO. A. Palau and S. Valencia contributed equally to this work.Peer reviewe

Piezas unidas de cerámicas superconductoras texturadas de TrBa2Cu3O7, donde Tr significa tierra rara o Ytrio, y proceso de unión basado en láminas de AG como agente fundente

Referencia OEPM: P200300081.-- Fecha de solicitud: 14/01/2003.-- Titulares: Consejo Superior de Investigaciones Científicas (CSIC).Un nuevo proceso de fabricación de uniones superconductoras entre dos piezas de cerámicas superconductoras ha sido desarrollado en el cual el agente fundente es una lámina de plata con un grosor bien determinado. La composición típica de la cerámica superconductora será TrBa2Cu3O7-Tr2BaCuO5, donde Tr significa Tierra rara o Ytrio. Este proceso permite fabricar productos cerámicos superconductores con formas complejas en los cuales las corrientes críticas a través de las uniones permanecen tan elevadas como las de las cerámicas originales antes de unirse.Peer reviewe

Geometrically controlled ratchet effect with collective vortex motion

© 2015 IOP Publishing Ltd and Deutsche Physikalische Gesellschaft. Rectified flux motion arising from the collective effect of many interacting vortices is obtained in a specially designed superconducting device. Ratchet structures with different asymmetric pinning potentials are generated by tuning the size, depth, and distribution of triangular blind-antidots in a high-temperature superconducting film. We experimentally and theoretically demonstrate that the amplitude and sign of the rectified vortex motion can be finely tuned with the pattern geometry. Two different dynamical regimes depending on the nature of vortices initiating the dissipation are identified, which can control the rectified vortex motion.This work has been supported by MINECO(MAT2014-51778-C2-1R, MAT2012-35370, CSD2007-0041, IPT- 2011-1090-920000), Generalitat de Catalunya (SGR2014-00753, 2014SGR150, XaRMAE), EU-FP7 NMP-LA- 2012-280432 EUROTAPES project and Cost Action MP1201.VR acknowledges the JAE-CSIC PhD grant. AS acknowledges funding from an ICREA Academia award.Peer Reviewe

Solution design for low-fluorine trifluoroacetate route to YBa2Cu3O7 films

We present our work in the preparation of metallorganic precursor solutions with reduced fluorine content, able to fulfil the requirements for high-performance superconducting YBCO epitaxial layers as a promising approach to low cost and scalable coated conductors. Six different solutions using different quantities of fluorine and non-fluorine carboxylate precursors with a total amount of fluorine from 10 to 50% that of standard trifluoroacetic acid (TFA) solutions. For stabilization purposes different coordinating agents have been used and the solution rheology has been modified for proper substrate wettability. Thermal decomposition analysis and infrared spectroscopy performed directly in films, have revealed that the decomposition takes place in two consecutive stages around 265 and 310 °C respectively, and nuclear magnetic resonance (NMR) analysis could unveil the chemical reactions taking place in the solution. Using the solutions with 20% fluorine and upon optimization of the growth process parameters, YBCO layers with T and J (77 K) of 90 K and 4 MA cm are obtained.The authors acknowledge the financial support from MICINN (Consolider NANOSELECT, CSD2007-00041, MAT 2011- 28874-C02, MAT2014-51778-C2-2-R also with FEDER support); Generalitat de Catalunya (Pla de Recerca 2014- SGR-753 and XaRMAE), and EU (FP7 NMP-LA-2012- 280432 EUROTAPES project and MP1201 Cost action).Peer Reviewe

Epitaxial YBa2Cu3O7-x nanocomposite thin films from colloidal solutions

A methodology of general validity to prepare epitaxial nanocomposite films based on the use of colloidal solutions containing different crystalline preformed oxide nanoparticles (ex situ nanocomposites) is reported. The trifluoroacetate (TFA) metal-organic chemical solution deposition route is used with alcoholic solvents to grow epitaxial YBaCuO (YBCO) films. For this reason stabilizing oxide nanoparticles in polar solvents is a challenging goal. We have used scalable nanoparticle synthetic methodologies such as thermal and microwave-assisted solvothermal techniques to prepare CeO and ZrO nanoparticles. We show that stable and homogeneous colloidal solutions with these nanoparticles can be reached using benzyl alcohol, triethyleneglycol, nonanoic acid, trifluoroacetic acid or decanoic acid as protecting ligands, thereby allowing subsequent mixing with alcoholic TFA solutions. An elaborate YBCO film growth analysis of these nanocomposites allows the identification of the different relevant growth phenomena, e.g. nanoparticles pushing towards the film surface, nanoparticle reactivity, coarsening and nanoparticle accumulation at the substrate interface. Upon mitigation of these effects, YBCO nanocomposite films with high self-field critical currents (J ∼ 3-4 MA cm at 77 K) were reached, indicating no current limitation effects associated with epitaxy perturbation, while smoothed magnetic field dependences of the critical currents at high magnetic fields and decreased effective anisotropic pinning behavior confirm the effectiveness of the novel developed approach to enhance vortex pinning. In conclusion, a novel low cost solution-derived route to high current nanocomposite superconducting films and coated conductors has been developed with very promising features.All authors acknowledge the EU (EU-FP7 NMP-LA-2012-280432 EUROTAPES project). ICMAB acknowledges MINECO (MAT2014-51778-C2-1-R) and Generalitat de Catalunya (2014SGR 753 and Xarmae). UGhent acknowledges the Special Research Fund (BOF), the Research Foundation Flanders (FWO) and the Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT). TEM microscopy work was conducted in the Catalan Institute of Nanoscience and Nanotechnology (ICN2). The authors acknowledge the ICN2 Electron Microscopy Division for offering access to their instruments and expertise. Part of the STEM microscopy work was conducted in 'Laboratorio de Microscopias Avanzadas' at the Instituto de Nanociencia de Aragon—Universidad de Zaragoza. The authors acknowledge the LMA-INA for offering access to their instruments and expertise. JG and MC also acknowledge the Ramon y Cajal program (RYC-2012-11709 and RYC-2013-12448 respectively).Peer Reviewe

1<i>s</i>2<i>p</i> resonant inelastic X-ray scattering combined dipole and quadrupole analysis method

In this study an analysis strategy towards using the resonant inelastic X-ray scattering (RIXS) technique more effectively compared with X-ray absorption spectroscopy (XAS) is presented. In particular, the question of when RIXS brings extra information compared with XAS is addressed. To answer this question the RIXS plane is analysed using two models: (i) an exciton model and (ii) a continuum model. The continuum model describes the dipole pre-edge excitations while the exciton model describes the quadrupole excitations. Applying our approach to the experimental 1s2p RIXS planes of VO2 and TiO2, it is shown that only in the case of quadrupole excitations being present is additional information gained by RIXS compared with XAS. Combining this knowledge with methods to calculate the dipole contribution in XAS measurements gives scientists the opportunity to plan more effective experiments.</jats:p

Effectiveness of a healthcare-based mobile intervention on sedentary patterns, physical activity, mental well-being and clinical and productivity outcomes in office employees with type 2 diabetes: study protocol for a randomized controlled trial

Background: Prolonged sedentary time is associated with an increased incidence of chronic disease including type 2 diabetes mellitus (DM2). Given that occupational sedentary time contributes signifcantly to the total amount of daily sedentariness, incorporating programmes to reduce occupational sedentary time in patients with chronic disease would allow for physical, mental and productivity benefts. The aim of this study is to evaluate the short-, medium- and long-term efectiveness of a mHealth programme for sitting less and moving more at work on habitual and occupational sedentary behaviour and physical activity in ofce staf with DM2. Secondary aims. To evaluate the efectiveness on glycaemic control and lipid profle at 6- and 12-month follow-up; anthropometric profle, blood pres‑ sure, mental well-being and work-related post-intervention outcomes at 3, 6 and 12months. Methods: Multicentre randomized controlled trial. A sample size of 220 patients will be randomly allocated into a control (n=110) or intervention group (n=110), with post-intervention follow-ups at 6 and 12months. Health professionals from Spanish Primary Health Care units will randomly invite patients (18–65 years of age) diagnosed with DM2, who have sedentary ofce desk-based jobs. The control group will receive usual healthcare and information on the health benefts of sitting less and moving more. The intervention group will receive, through a smartphone app and website, strategies and real-time feedback for 13weeks to change occupational sedentary behaviour. Variables: (1) Subjective and objective habitual and occupational sedentary behaviour and physical activity (Workforce Sit‑ ting Questionnaire, Brief Physical Activity Assessment Tool, activPAL3TM); 2) Glucose, HbA1c; 3) Weight, height, waist circumference; 4) Total, HDL and LDL cholesterol, triglycerides; (5) Systolic, diastolic blood pressure; (6) Mental well being (Warwick-Edinburgh Mental Well-being); (7) Presenteeism (Work Limitations Questionnaire); (8) Impact of work on employees´ health, sickness absence (6th European Working Conditions Survey); (9) Job-related mental strain (Job Content Questionnaire). Diferences between groups pre- and post- intervention on the average value of the vari‑ ables will be analysed. Discussion: If the mHealth intervention is efective in reducing sedentary time and increasing physical activity in ofce employees with DM2, health professionals would have a low-cost tool for the control of patients with chronic disease.The study was funded by Fondo de Investigación Sanitaria, Instituto de Salud Carlos III (PI17/01788) and the predoctoral research grant Isabel Fernández 2020 from the Spanish Society of Family and Community Medicine (semFYC). The funders had no role in the design, analysis, data interpretation or writing of the manuscript

Inkjet-printed chemical solution Y₂O₃ layers for planarization of technical substrates

The implementation of the Chemical Solution Deposition (CSD) methodology with 23 the Drop on Demand (DoD) inkjet printing (IJP) technology has been successfully employed to 24 develop a Solution Deposition Planarization (SDP) method. We have used nanocrystalline yttrium 25 oxide (Y₂O₃) to decrease the roughness of technical metallic substrates by filling the surface 26 imperfections and thus avoiding costly polishing steps. This alternative process represents an 27 outstanding methodology to reduce the final cost of the 2G coated conductors manufacturing. 28 Two Y₂O₃ metalorganic precursor inks formulations were successfully developed and tested to 29 obtain surfaces as smooth as possible with adequate mechanical properties to hold the internal 30 stresses developed during the subsequent layers growth. 31 By using these inks as precursors for IJP and after a proper tuning of the rheological and 32 wetting parameters, we firstly obtained short length uniform 100nm-thick Y₂O₃-SDP films on 33 unpolished stainless steel substrate from Bruker HTS. The scalability of the reel to reel (R2R)-IJP 34 process to 100m is then demonstrated on metallic substrates as well. A complete characterization of 35 the prepared short and long length SDP-Y₂O₃ inkjet-printed layers was carried out by optical 36 microscopy, FIB-SEM (Focus Ion Beam coupled to Scanning Electron Microscopy), XRD (X-Ray 37 Diffraction), AFM (Atomic Force Microscopy), reflectometry and nanoindentation techniques. Then, 38 the morphology, thickness, crystallinity and mechanical properties were evaluated, together with 39 the surface roughness in order to assess the resulting layer planarity. The impact of planarity was 40 additionally studied via growth of biaxially textured buffer layers as well as further functional 41 layers. 1.1µm-thick YSZ layers with in-plane textures better than the SS polished reference were 42 successfully deposited on top of the 100 nm SDP-Y2O3 films yielding 50% of Ic in contrast to the 43 standard reference

Influence of growth temperature on the pinning landscape of YBa2Cu3O7−δ films grown from Ba-deficient solutions

Cuprate coated conductors are promising materials for the development of large-scale applications, having superior performance over other superconductors. Tailoring their vortex pinning landscape through nanostructure engineering is one of the major challenges to fulfill the specific application requirements. In this work, we have studied the influence of the growth temperature on the generation of intrinsic pinning defects in YBa2Cu3O7-δ films grown by chemical solution deposition using low Ba precursor solutions. We have analysed the critical current density as a function of the temperature, applied magnetic field magnitude and orientation, J c(T,H,θ), to elucidate the nature and strength of pinning sites and correlate the microstructure of the films with their superconducting performance. An efficient pinning landscape consisting of stacking faults and associated nanostrain is naturally induced by simply tuning the growth temperature without the need to add artificial pinning sites. Samples grown at an optimized temperature of 750 °C show very high self-field J c values correlated with an overdoped state and improved J c(T,H,θ) performances.This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom Research and Training Programme 2014–2018 and 2019–2020 under Grant Agreement No. 633 053. The views and opinions expressed herein do not necessarily reflect those of the European Commission. TEM analysis was funded from the EU Horizon 2020 research and innovation program under grant agreement 823717—ESTEEM3. The authors acknowledge financial support from Spanish Ministry of Economy and Competitiveness through the 'Severo Ochoa' Programme for Centres of Excellence in R&D (SEV-2015-0496 and CEX2019-000917-S), SuMaTe RTI2018-095853-B-C21, co-financed by the European Regional Development Fund), the Catalan Government with Grant 2017-SGR-1519 and the EU COST action NANOCOHYBRI CA16218. We also acknowledge the Scientific Services at ICMAB. J A like to thank the UAB PhD program in Materials Science.With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000917-S).Peer reviewe

Geometrically controlled ratchet effect with collective vortex motion

Rectified flux motion arising from the collective effect of many interacting vortices is obtained in a specially designed superconducting device. Ratchet structures with different asymmetric pinning potentials are generated by tuning the size, depth, and distribution of triangular blind-antidots in a high-temperature superconducting film. We experimentally and theoretically demonstrate that the amplitude and sign of the rectified vortex motion can be finely tuned with the pattern geometry. Two different dynamical regimes depending on the nature of vortices initiating the dissipation are identified, which can control the rectified vortex motion