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The anisotropy of the critical current density Jc was determined from angular critical current measurements for YBa2Cu3O6+x (YBCO) thin films laser deposited from a nanograined and a BaZrO3-doped nanograined target. In quantitative analysis using Blatter scaling the effective Jc anisotropy was found to be much smaller than for standard YBCO films.

A simple model based on distributions of twin boundaries, dislocations, and BaZrO 3 nanorods is presented to describe the J c properties of undoped and BaZrO 3 ͑BZO͒-doped YBa 2 Cu 3 O x thin films. The model accurately describes the shape of J c ͑B , T͒ curves of the films, when the pinning site distributions are taken from distributions of twin spacings and BZO nanorods from transmission electron microscope images. Thus, assuming that the model can be used for prediction of the J c properties, we conclude that for enhancement of undoped films more crystalline defects are needed and for doped films a dopant that would create slightly larger rods would be optimal.

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