22-27 September 2019
Hyatt Regency Hotel Vancouver
Canada/Pacific timezone

Tue-Mo-Po2.10-08 [80]: Improved performance at low temperatures of CSD-grown YxGd1-xBa2Cu3O7-BaHfO3 nanocomposite films

24 Sep 2019, 08:45
2h
Level 2 Posters 2

Level 2 Posters 2

Speaker

Pablo Cayado (Karlsruhe Institute of Technology (KIT))

Description

High-temperature superconductors are becoming engineering materials, e.g. as commercially available long-length tapes (coated conductors, CCs). Among them, REBa2Cu3O7-x (REBCO, RE rare earth) compounds have emerged as excellent candidates due to their high-field current carrying capacity. Their properties enhance even further when REBCO nanocomposites are formed, i.e., nanoscale non-superconducting secondary phases are introduced into the superconducting matrix, which pin the vortices. Through this, the performances improve in a wide range of applied magnetic fields and temperatures.
Chemical solution deposition (CSD) has been demonstrated to be a scalable, versatile and cost-effective technique for the preparation of REBCO films with embedded secondary phases, starting from a complex metalorganic precursor solution. In such films, the nanoparticles form spontaneously during the film growth and tend to orient randomly in the REBCO matrix. This creates a high density of defects generating nanostrain within the REBCO matrix, which ultimately leads to a strong enhancement of the isotropic pinning contribution.
In this work, we present the superconducting properties of 220 nm single-RE-Ba2Cu3O7-x (RE = Yb, Er, Ho, Y, Dy, Gd, Sm, and Nd) films on different substrates to develop a deeper understanding of their processing windows and properties at different temperatures. Also, we include a complete study about (Y/Gd)BCO + 12 mol% BaHfO3 nanocomposite films. These films were obtained in a high-quality after a complex growth-parameter optimization for different Y/Gd ratios. Transport measurements of the optimized films were carried out at different temperatures. The results show that the best properties are obtained for different Y/Gd ratios depending on the temperature: at 77 K, where the proximity to the superconducting transition is crucial, GdBCO+12mol% BaHfO3 has the largest critical current density Jc while at 30 K the Y0.5Gd0.5BCO+12 mol% BaHfO3 films exhibit the highest values at self-field. This behavior was understood by studying the microstructure of these samples by advanced TEM measurements. The distribution of Y and Gd in the mixed phases enrichens the pinning landscape making these films more effective at lower temperatures.

Primary authors

Dr Manuela Erbe (Karlsruhe Institute of Technology (KIT)) Dr Jens Haenisch (Karlsruhe Institute for Technology) Prof. Bernhard Holzapfel (KIT Karlsruhe) Dr Thomas Thersleff (Stockholm University, Department of Materials and Environmental Chemistry) Dr Hannes Rijckaert Rijckaert (Ghent University, SCRiPTS, Dept. of Chemistry) Pablo Cayado (Karlsruhe Institute of Technology (KIT))

Presentation Materials