Synergetic combination of different types of defect to optimize pinning landscape using BaZrO3-doped YBa2Cu3O7

• Published in: Nature materials Vol. 8; no. 5; pp. 398 - 404
• Main Authors: Maiorov, B., Baily, S. A., Zhou, H., Ugurlu, O., Kennison, J. A., Dowden, P. C., Holesinger, T. G., Foltyn, S. R., Civale, L.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01-05-2009; Nature Publishing Group
• Subjects: Biomaterials; Chemistry and Materials Science; Condensed Matter Physics; Electric currents; Electricity; Growth kinetics; High temperature; Materials Science; Nanoparticles; Nanotechnology; Optical and Electronic Materials; Ratios; Superconductors
• ISSN: 1476-1122; 1476-4660
• DOI: 10.1038/nmat2408

Retaining a dissipation-free state while carrying large electrical currents is a challenge that needs to be solved to enable commercial applications of high-temperature superconductivity. Here, we show that the controlled combination of two effective pinning centres (randomly distributed nanoparticles and self-assembled columnar defects) is possible and effective. By simply changing the temperature or growth rate during pulsed-laser deposition of BaZrO
3
-doped YBa
2
Cu
3
O
7
films, we can vary the ratio of these defects, tuning the field and angular critical-current (
I
c
) performance to maximize
I
c
. We show that the defects’ microstructure is governed by the growth kinetics and that the best results are obtained with a mixture of splayed columnar defects and random nanoparticles. The very high
I
c
arises from a complex vortex pinning landscape where columnar defects provide large pinning energy, while splay and nanoparticles inhibit flux creep. This knowledge is used to produce thick films with remarkable
I
c
(
H
) and nearly isotropic angle dependence.
Applications of high-temperature superconductivity rely on transporting a large current without dissipation. It is now shown how the inclusion of a combination of two types of defect can be used to control and optimize the performance of the high-temperature superconductor YBa
2
Cu
3
O
7
.