Large anisotropic critical magnetization currents in single-crystal YBa2Cu3O7- delta.

Magnetization measurements on single crystals of $\mathrm{Y}{\mathrm{Ba}}_{2}{\mathrm{Cu}}_{3}{\mathrm{O}}_{7\ensuremath{-}\ensuremath{\delta}}$ show strong anisotropic flux pinning with critical magnetization current densities of 1.4\ifmmode\times\else\texttimes\fi{}${10}^{6}$ A/${\mathrm{cm}}^{2}$. The critical magnetization currents fall sharply with temperature in both single-crystal and polycrystalline samples. The high critical magnetization current densities can be reduced by nearly two orders of magnitude by annealing.