Elsevier, Physica C: Superconductivity and its Applications, 1-3(177), p. 165-170
DOI: 10.1016/0921-4534(91)90314-o
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Measurements of the depinning field and the critical current density on epitaxially grown c-axis oriented YBa2Cu3O7 films were performed under variation of the angle between the field direction and the c-axis of the film with high angular resolution (??0.04). The critical current densities were measured on a 10 ?m wide and 100 ?m long strip by applying a 1 ?V criterion. The dependence jc() obtained for low temperatures can be well explained by a model published by Tachiki and Takahashi. For higher temperatures and higher magnetic fields additional structures appear. The measured angular dependence of the depinning field shows a cusp for =90°. The complete angular dependence Bdp() can be explained by simply taking into account the anisotropy of the upper critical field.