The Biaxial Strain Dependence of <italic>J</italic>_C of a (RE)BCO Coated Conductor at 77 K in Low Fields

Abstract

Recently, we designed and commissioned a 'crossboard' sample holder which can apply biaxial strains in the plane of a (RE)BCO coated conductor. It allows us to measure the critical current density for arbitrary combinations of x-and y-strain. Understanding the in-field, in-plane, biaxial strain dependence of a tape's ( , , ) is crucial for applications such as CORC® or Roebel cables, as the cables are subjected to multiaxial strains during manufacturing and operation. Here we present experimental data for ( , ,) on a SuperPower SCS4050 APC tape in magnetic fields up to 0.7 T, at 77 K. We also outline a theoretical model for the biaxial strain dependence of and use it to parameterise our data and show that the fraction of A-domains and B-domains are roughly equal ( = 0.49 ± 0.03) and that the strain sensitivity of the critical temperature is 1.8 ± 0.1 K% -1 and -1.3 ± 0.1 K% -1 along their a-and b-axes respectively, for all the domains in this (RE)BCO tape. For the first time, we show both parabolic and linear strain dependencies of in a single tape by changing the angle between the applied strain direction and the twin boundaries in the (RE)BCO layer.  Index Terms-Critical current, strain measurement, 2G HTS conductors, cuprates.

System for characterizing the electromechanical properties of REBCO coated conductors through simultaneous measurements of critical current and mechanical load

“…Unlike the IBAD/MOCVD CC tape, the a-and b-axes are in the same direction as the current flow. Moreover, when the sample has a <100> orientation, it exhibits weak strain behavior, and when the strain is applied parallel to the direction of the CC tape, it will eventually lead the inverted parabolic behavior observed in figures 9(a) and (b) [31]. This particular behavior did not vary between repetitions of the test; little scattering was observed across the five tests for the two CC tapes.…”

Influence of HTS tape arrangement on the transverse compression performance of copper former CORC cables

“…Under the action of these stress, the HTS tape in the cable will generate strain. Once the strain of the HTS tape in CORC cables exceeds its critical strain, its current carrying capacity will be irreversibly decreased [1][2][3][4][5][6]. Therefore, in recent years, the research on mechanical properties of CORC cables has attracted extensive attention.…”

Resistivity Measurements of the Strain, Temperature and Angular Dependence of the Upper Critical Field of REBCO Tapes up to 8 T

“…Hence, to understand and improve HTS REBCO tapes we need a more complete understanding of how the entire distribution of critical parameters varies with strain. Eventually we will need to progress beyond assuming the strain dependence along the c-axis of REBCO is negligible [4], and measure the effect of strain on quasi-single crystals and tapes loaded with pinning sites [12]. The miniature strain-board presented here will help with the collection of some of the huge range of critical current versus magnetic field, temperature, strain and irradiation dose data sets [13] that will be required to understand and parameterise complex anisotropic high J c REBCO tapes.…”

“…1). This novel design allows small tape samples (7mm) to be measured, whereas previous variable-strain studies have used long samples (≈ 20 mm) [12]. This strain-board can therefore fit inside a Physical Property Measurement System (PPMS) [15] for fast and efficiently automated, variable magnetic field and temperature measurements, as well as inside small-bore pulsed field facilities [16].…”