Abstract
Measurements of critical temperature Tc in superconducting YBa2Cu3O6.9 films with reduced long-range structural order show the validity of the empirical scaling relation ΔTc ∝ rc−2 between disorder-induced reduction of Tc and structural coherence length rc in the ab-plane. This result is quantitatively explained by the disorder-induced confinement of the charge carriers within each ordered domain of size rc. Our analysis of the data based on this picture enables us to precisely determine the Ginzburg-Landau superconducting coherence length in the ab-plane, ξab = 1.41 ± 0.04 nm.