Strain Dependence of Superconducting Properties for GdBCO Coated Conductor in High Field Under Tensile Load

The strain dependence of T
_c
and I
_c
for the GdBCO coated conductor was measured at 77 and 4.2 K in magnetic fields. T
_c
decreased with increasing applied tensile strain. For the I
_c
measurements, the magnetic field was applied in the direction parallel to the c-axis (perpendicular to the tape surface). I
_c
in fields was degraded with increasing strain, and the strain dependence of I
_c
increased with increasing magnetic field. The ratio of the I
_c
degradation at 4.2 K was smaller than that at 77 K. These results mean that the T
_c
degradation is one of the reasons for I
_c
degradation at 77 K at least. Further, in order to understand the strain effect at 4.2 K, the internal strain of the GdBCO coated conductor under tensile strain was measured using synchrotron radiation. It was found that the strain behavior for the a-axis is different from that for the b-axis. This result suggests that the strain dependence of I
_c
for GdBCO coated conductors under external tensile strain is related with the T
_c
degradation behavior of the crystal.