Biaxial Strain Measurements of Jc on a (RE)BCO Coated Conductor

Greenwood, Jack R.; Surrey, Elizabeth; Hampshire, Damian P.

Abstract

For several years it has been possible to measure the uniaxial strain dependence of the critical current density JC (ε) of (RE)BCO coated conductors [(RE)BCO tapes] and a parabolic strain dependence of JC (ε) has been observed. To improve our understanding of how strain affects the electrical and mechanical properties of a SuperPower APC SCS4050 (RE)BCO tape, we have created a biaxial sample holder that can apply arbitrary strains along both the x- and y-axes of a (RE)BCO tape simultaneously. It can be used to measure JC for independently controllable applied x and y strains ranging from −0.50% εx 0.30% to −0.15% εy 0.20%, respectively, at 77 K. We present the results of JC measurements over this strain range at 77 K in magnetic fields of up to 0.7 T. We show that we obtain the standard parabolic relationship for JC (εx), with a peak in JC occurring at εxP = −0.01%. We also show that when we apply an additional y strain of εy = −0.08% the peak in JC moves to εxP = 0.4%, which cannot be explained by considering the differential strains produced by nonsuperconducting components of the tape and sample holder. In addition, the value of JC at the peak increases considerably by 11%.

Citation

Greenwood, J. R., Surrey, E., & Hampshire, D. P. (2018). Biaxial Strain Measurements of Jc on a (RE)BCO Coated Conductor. IEEE Transactions on Applied Superconductivity, 28(4), Article 8400705. https://doi.org/10.1109/tasc.2018.2793282

• Journal Article Type: Article
• Acceptance Date: Jan 10, 2018
• Online Publication Date: Jan 15, 2018
• Publication Date: Jun 1, 2018
• Deposit Date: Mar 15, 2018
• Publicly Available Date: Mar 16, 2018
• Journal: IEEE Transactions on Applied Superconductivity
• Print ISSN: 1051-8223
• Electronic ISSN: 1558-2515
• Publisher: Institute of Electrical and Electronics Engineers
• Peer Reviewed: Peer Reviewed
• Volume: 28
• Issue: 4
• Article Number: 8400705
• DOI: https://doi.org/10.1109/tasc.2018.2793282
• Keywords: Critical current, strain measurement, 2G HTS conductors, cuprates
• Public URL: https://durham-repository.worktribe.com/output/1337502