Temporal Evolution of Defects and Related Electric Properties in He-Irradiated YBaCuO Thin Films.

Thin films of the superconductor YBaCuO (YBCO) were modified by low-energy light-ion irradiation employing collimated or focused He beams, and the long-term stability of irradiation-induced defects was investigated. For films irradiated with collimated beams, the resistance was measured in situ during and after irradiation and analyzed using a phenomenological model. The formation and stability of irradiation-induced defects are highly influenced by temperature.

Ordered Bose Glass of Vortices in Superconducting YBaCuO Thin Films with a Periodic Pin Lattice Created by Focused Helium Ion Irradiation.

The defect-rich morphology of YBaCuO (YBCO) thin films leads to a glass-like arrangement of Abrikosov vortices which causes the resistance to disappear in vanishing current densities. This vortex glass consists of entangled vortex lines and is identified by a characteristic scaling of the voltage-current isotherms. Randomly distributed columnar defects stratify the vortex lines and lead to a Bose glass.