Relation Between the Crystal Axis and the Strain Dependence of Critical Current Under Tensile Strain for GdBCO Coated Conductors

The strain and the critical current of the GdBCO coated conductor were investigated in order to understand the mechanism of the strain effect for a coated conductor. The internal strain behaviors of the longitudinal, width, and thickness directions were measured by the X-rays of the synchrotron radiation. From these results, the residual strains of a, b, and c-axes for the GdBCO crystal were estimated. In addition, the strain dependence of the critical current and the n-value at 4.2 and 77 K were measured under the tensile strain. The relationship between superconducting properties and the triaxial strain in the GdBCO crystal of the coated conductors is discussed.