Anisotropies in the magnetic penetration depth and critical current density of R1Ba2Cu3O7-x (R=Y or Ho), measured on magnetically-aligned powder composites

Dispersed, uniaxially-aligned powder composites of R₁Ba ₂Cu₃O_7-x (R=Y or Ho) were formed by suspending the powder in a liquid organic matrix that was then solidified in a magnetic field. From the observed particle dimensions and magnetic susceptibility measurements for fields applied either parallel or perpendicular to the Cu-O planes, the authors infer anisotropies in the superconducting magnetic penetration depth λ. From the magnetization hysteresis in the mixed state they derive relative anisotropies in the critical-current densities J_c . The observed anisotropies are qualitatively similar for both rare-earth-based materials but show some quantitative distinctions