Investigation of the crystallization process of CSD-ErBCO on IBAD-substrate via DSD approach

REBa$_{2}$Cu$_{3}$O$_{7-δ}$ (REBCO, RE: rare earth, such as Y and Gd) compounds have been extensively studied as a superconducting layer in coated conductors. Although ErBCO potentially has better superconducting properties than YBCO and GdBCO, little research has been made on it, especially in chemical solution deposition (CSD). In this work, ErBCO films were deposited on IBAD (ion-beam-assisted-deposition) substrates by CSD with low-fluorine solutions. The crystallization process was optimized to achieve the highest self-field critical current density (J$_{c}$) at 77 K. Commonly, for the investigation of a CSD process involving numerous process factors, one factor is changed keeping the others constant, requiring much time and cost. For more efficient investigation, this study adopted a novel design-of-experiment technique, definitive screening design (DSD), for the first time in CSD process. Two different types of solutions containing Er-propionate or Er-acetate were used to make two types of samples, Er-P and Er-A, respectively. Within the investigated range, we found that crystallization temperature, dew point, and oxygen partial pressure play a key role in Er-P, while the former two factors are significant for Er-A. DSD revealed these significant factors among six process factors with only 14 trials. Moreover, the DSD approach allowed us to create models that predict J$_{c}$ accurately. These models revealed the optimum conditions giving the highest J$_{c}$ values of 3.6 MA/cm$^{2}$ for Er-P and 3.0 MA/cm$^{2}$ for Er-A. These results indicate that DSD is an attractive approach to optimize CSD process

Impact of a Primary Care Antimicrobial Stewardship Program on Bacterial Resistance Control and Ecological Imprint in Urinary Tract Infections

Antimicrobial stewardship programs (ASPs) are a central component in reducing the overprescription of unnecessary antibiotics, with multiple studies showing benefits in the reduction of bacterial resistance. Less commonly, ASPs have been performed in outpatient settings, but there is a lack of available data in these settings. We implemented an ASP in a large regional outpatient setting to assess its feasibility and effectiveness. Over a 5-year post-implementation period, compared to the pre-intervention period, a significant reduction in antibiotic prescription occurred, with a reduction in resistance in E. coli urinary isolates. ASP activities also were found to be cost-effective, with a reduction in medication prescription

Transport measurements in single-grain GdBCO+Ag bulk superconductors processed by infiltration growth

Funder: University of GenevaAbstractTransport measurements performed on a cross-sectional slice prepared from a bulk GdBa2Cu3O7-x-Ag single-grain superconductor of 25 mm in diameter are described and the results presented. The sample, which was fabricated via the buffer-assisted top-seeded infiltration growth process, was capable of trapping a maximum magnetic field of ~ 1 T at 77 K. Transport measurements on superconducting, bulk single-grain RE-Ba-Cu-O [(RE)BCO] samples are generally very challenging due to their large critical current densities and poor mechanical properties. We present a straightforward and reliable approach to prepare reproducibly specimens from the parent single grain and results of transport property measurements on these samples in a commercial Physical Property Measurement System (PPMS). Critical current densities determined via magnetic and transport measurements are compared and discussed.</jats:p

Comparative study of CSD-grown RE BCO films with different rare earth elements: processing windows and T c

REBa$_{2}$Cu$_{3}$O$_{7}$−x (REBCO, RE = rare earth) compounds with different single RE elements were grown via TFA-MOD (metal-organic deposition of trifluoroacetates) to clarify their T$_{c}$ values when grown by the same preparation method and their processing windows; here: the crystallisation temperatures at a constant process gas composition (pO$_{2}$, pH$_{2}$O). We focussed on the lanthanides (Ln) Nd, Sm, Gd, Dy, Ho, Er and Yb as substituents for Y in the REBCO phase and investigated their growth behaviour in terms of resulting physical (inductive T$_{c}$ and J$_{c}$(77 K)) and structural properties (determined by XRD, SEM, TEM). All phases were grown as pristine films on LaAlO$_{3}$ and SrTiOx$_{3}$ and compared to their respective nanocomposites with 12 mol% BaHfO$_{3}$ for in-field pinning enhancement. With regard to T$_{c}$ and J$_{c}$(77 K), the optima of both values shift towards higher growth temperatures for increasing and decreasing RE ion size with respect to yttrium. Highest T$_{c}$ values achieved so far do not show a trend that can solely be related to the RE ionic size. On the contrary, T$_{c,90}$ values of the LnBCO compounds from Sm to Er range between 94.0 and 95.3 K and are, therefore, significantly larger than the highest values of the average-size non-lanthanide, Y, with T$_{c,90}$ = 91.5 K. J$_{c,sf}$ values at 77 K seem to plateau between 5 and 6 MA cm$^{-2}$ from Sm to Er and are again clearly above the maximum values we ever achieved for Y with 4.2 MA cm$^{-2}$. REBCO phase formations of the very small Yb and large Nd turned out to be more difficult and require further adjustment of growth parameters. All REBCO phases investigated here show distinct dependences of T$_{c}$ on the lattice parameter c

Unique nanostructural features in Fe, Mn-doped YBCO thin films

An attempt to grow a thin epitaxial composite film of YBa2Cu3O7-δ (YBCO) with spinel MnFe2O4 (MFO) nanoparticles on a LAO substrate using the CSD approach resulted in a decomposition of the spinel and various doping modes of YBCO with the Fe and Mn cations. These nanostructural effects lead to a lowering of Tc and a slight Jc increase in field. Using a combination of advanced transmission electron microscopy (TEM) techniques such as atomic resolution high-angle annular dark field scanning transmission electron microscopy, energy dispersive X-ray spectroscopy and electron energy-loss spectroscopy we have been able to decipher and characterize the effects of the Fe and Mn doping on the film architecture. The YBaCuFeO5 anion-deficient double perovskite phase was detected in the form of 3D inclusions as well as epitaxially grown lamellas within the YBCO matrix. These nano-inclusions play a positive role as pinning centers responsible for the Jc/Jsf (H) dependency smoothening at high magnetic fields in the YBCO-MFO films with respect to the pristine YBCO films.The authors gratefully acknowledge Prof. Dr. A. Abakumov and Dr. J. Gazquez for discussions and corrections. Part of this work was performed within the framework of the EUROTAPES project (FP7-NMP.2011.2.2-1 Grant no. 280432), funded by the European Union. ICMAB research was financed by the Ministry of Economy and Competitiveness, and FEDER funds under the projects MAT2011-28874-C02-01, MAT2014-51778-C2-1-R, ENE2014-56109-C3-3-R and Consolider Nanoselect CSD2007-00041, and by Generalitat de Catalunya (2009 SGR 770, 2015 SGR 753 and Xarmae). ICMAB acknowledges support from Severo Ochoa Program (MINECO, Grant SEV-2015-0496).Peer reviewe