In situ strain measurements of superconducting composites by depth and layer sensitive X-ray diffraction technique utilizing synchrotron radiation

Axial strain of Dy123 tape during tensile deformation was measured in situ with in-plane synchrotron radiation diffraction. Strain in Dy123 epitaxial layer increased with tensile strain, and remain constant after multiple cracking of the layer. With anomalous dispersion at Dy L3 edge, the Bragg peak from Dy123 layer was identified. Measured strain for Ag layer coated on the Dy123 suggests earlier yield of Ag. Strain of the layers in Dy123-based coated superconductor composite tapes under tensile load has been evaluated by in situ synchrotron radiation diffraction near the L3 absorption edge of Dy. In the present work, in-plane diffraction profile of the materials under tensile deformation with the scattering vector parallel to the axial load has been analyzed. The axial strain evaluated from the Dy123 peaks agreed with the average sample strain obtained from a separate mechanical test in elastic region. After Lueders deformation started, the strain of the Dy123 layer remained almost constant, in agreement with a multiple fracture model for ductile-fragile composite materials. Anomalous dispersion effect was used to identify the origin of the Bragg peak.