Dimensional crossover and kosterlitz-thouless transition in high-temperature superconductors

Abstract We report detailed measurements of the electrical resistance ϱ of Y 1 Ba 2 Cu 3 O 7- X ceramic and thin film samples and of a Bi 2 CaSr 2 Cu 2 O 8 single crystal. The transition regions analyzed in terms of the Aslamasov-Larkin theory, the Lawrence-Doniach theory and the Kosterlitz-Thouless model indicate a universal critical behaviour of ϱ in distinct HTSC due to a successive change of their effective dimension with temperature. The obtained parameters partly confirm the theoretical predictions as well as suggest the influence of disorder effects.