Angle-dependent broadening and anomalies of the resistivity transition in YBa2Cu3O7 single crystal

In a further study of the field-broadening of the resistive transition in high-T_c superconductors, resistivity measurements have been performed as a function of the direction of the applied field with respect to the crystallographic axes on a YBa₂Cu₃O₇ single-crystalline sample for field and current directions within the ab-plane over the full range of field orientations. The angular modulation in resistivity is compared wit predictions of flux-creep and flux-flow theories. Magneto-resistivity measurements have been performed at specific angles of the applied field with respect to the crystallographic directions. Saturation of the Lorentz-force effect for perpendicular field and current directions is found for fields larger than a critical value that is strongly temperature dependent. A complex resistivity anomaly is observed for fields parallel to the twin boundary.