Effects of Irradiation on Vicinal YBCO Thin Films

The achievable transport critical current densities in coated conductors are limited in part by low angle grain boundaries. Effects like vortex channeling found in these low angle boundaries at low fields can also be studied in vicinal thin films. The influence of neutron irradiation, a proven method for increasing magnetic and current carrying properties, on these effects was investigated in this work. An YBCO vicinal sample, grown on a SrTiO₃ substrate with the ab plane oriented at 6 degrees off parallel, was fabricated through pulsed layer deposition (PLD) and both transition temperature and transport current measurements were performed using a 2-axis probe. The sample was rotated at varying temperature in an applied magnetic field of up to 6 T. The angular dependence of the critical density was determined before and after an irradiation to a neutron fluence of 1 times 10²¹ m^-2 in the TRIGA Mark II reactor in Vienna.