In-Plane Anisotropy of Electrical Transport in YTbBaCuO Films.

We fabricated high-quality c-axis-oriented epitaxial YBaCuO films with 15% of the yttrium atoms replaced by terbium (YTBCO) and studied their electrical properties. The Tb substitution reduced the charge carrier density, resulting in increased resistivity and decreased critical current density compared to pure YBaCuO films. The electrical properties of the YTBCO films showed an in-plane anisotropy in both the superconducting and normal states that, together with the XRD data, provided evidence for, at least, a partially twin-free film.