Strong flux-pinning in epitaxial NdBa2Cu3O7-δ films with columnar defects comprised of self-assembled nanodots of BaZrO3

Epitaxial NdBa2Cu3O7-δ (NdBCO) films with and without the incorporation of self-assembled nanodots of BaZrO3 (BZO) were grown on rolling-assisted-biaxially-textured substrates (RABiTS) by pulsed laser deposition. Compared to epitaxial YBa2Cu3O7-δ (YBCO) films on RABiTS, NdBCO films are found to have superior performance in applied fields at all field orientations, suggesting the presence of an increased density of pinning centres. The incorporation of columns of self-assembled nanodots of BZO within the NdBCO films results in further enhancement of the in-field Jc at all field orientations. Jc varies as Jc∼H-α at intermediate fields, with α values for NdBCO and BZO-doped NdBCO films being ∼0.37 and ∼0.43, respectively, which are significantly lower than α∼0.52 for YBCO film. (rapid communication)