Vortex Pinning by Gold Nanorods in GdBa2Cu3O7−δ Thin Films

Gold nanorods were introduced into GdBa₂Cu₃O_7-delta (GdBCO) thin films to form artificial pinning centers. The incorporation of gold nanorods into the GdBCO films was achieved simply by attaching gold sheets to a GdBCO target in the pulsed laser deposition process. Transmission electron microscopy observation showed that gold nanorods grew parallel to the c-axis of the GdBCO Alms. Small angle X-ray scattering and scanning electron microscopy results indicated that matching field, B_Phi was increased with the amount of supplied gold. J_c - B characteristics in the field aligned with the c-axis at 50 and 65 K exhibited an anomalous shoulder ("peak effect") around at B_Phi, and the peak position was not dependent on the temperature. This suggests that the "peak effect" was originated from the matching effect between vortices and the gold nanorods.