Epitaxial thin films of YBa₂Cu₄O₈ superconductor deposited by laser ablation of solution derived complex targets

Abstract

We report here the successful fabrication of single phase epitaxial thin films of the superconductor YBa₂Cu₄O₈ (1-2-4) deposited on monocrystalline (100) substrates of yttriastabilized ZrO₂ using the technique of pulsed-laser ablation. The targets of 1-2-4 were fabricated through a novel low temperature synthesis technique whereby it was possible to synthesize reacted 1-2-4 pellets without the application of high oxygen pressure. In this report, the target material was composed of an unreacted solution derived Y-Ba-Cu (1-2-4)-complex. The films have superconducting transition temperatures varying from 70-80K and critical current densities higher than 5×10⁶ A/cm² below 60K. X-ray diffractograms indicate that the films are oriented with their c-axis perpendicular to the surface of the substrate.