Osamura, K. and Machiya, S. and Hampshire, D. P. (2016) 'Mechanism for the uniaxial strain dependence of the critical current in practical REBCO tapes.', Superconductor science and technology., 29 (6). 065019.
In order to elucidate the effect of uniaxial strain on the critical current of practical REBCO tapes (REBa2Cu3O7−d , RE = Y and Gd) fabricated by Superpower and SuNAM, two types of critical current measurements were carried out. In the first, the tape sample was attached directly to a universal testing machine and pulled under a tensile load. In the second, the tape was soldered to a Cu–Be springboard and then attached to the testing machine and then pushed or pulled in order to apply both tensile and compressive strains to the tape sample. An inverse parabolic behaviour was observed for the uniaxial strain dependence of the critical current of both tapes. Using synchrotron radiation, the local strain exerted on the REBCO layer was measured at room temperature under the conditions used for the two techniques for making I c measurements. On the basis of these room temperature data, the local strain exerted on the REBCO layer at 77 K was numerically evaluated. A one-dimensional chain model for current flow in the REBCO material with fractional lengths of A-domains and B-domains oriented along the uniaxial strain direction is proposed. The model can explain the parabolic strain behaviour of the critical current and shows that the strain at which the peak in I c occurs, is not only determined by pre-compression or pre-tension on the superconductor at the operating temperature, but also by the ratio of the fractional amounts of the two domains.
|Full text:||(AM) Accepted Manuscript|
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|Publisher Web site:||http://dx.doi.org/10.1088/0953-2048/29/6/065019|
|Publisher statement:||This is an author-created, un-copyedited version of an article published in Superconductor Science and Technology. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at 10.1088/0953-2048/29/6/065019|
|Date accepted:||15 April 2016|
|Date deposited:||04 August 2016|
|Date of first online publication:||06 May 2016|
|Date first made open access:||06 May 2017|
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