Abstract
Addition of nanosized material in YBa2Cu3O2-d to produce artificial pinning cores is benefit way to enhance the in-field current-carrying capacity and flux pinning properties. In this work, we report the impact of nano-dysprosium oxide particles (Dy2O3) with a size of 10 nm on the mechanisms and the strength of pinning centers of polycrystalline YBa2Cu3O2-d. Samples of YBa2Cu3O2-d + x Dy2O3 with x = 0.0 and 0.1 wt% were prepared via solid-state reaction way. X-ray diffraction and scanning electron microscope observations were performed to characterize the structure and the morphology of samples. Measurements of D.0 magnetization against applied magnetic field from -6 to +6 T were implemented to estimate the critical current density and verify the pinning mechanisms at different temperatures ranging from 77 down to 10 K. The orthorhombic YBCO structure is preserved in both samples, NP-Dy2O3 weakens the grains linkage, drops the zero resistive temperature Tc by 1.6 K and weakens the inter-granular critical current density. Over the measured temperature range and exterior magnetic fields, results showed higher intra-granular current density and a best ability to trap vortex in the 0.1Dy-YBCO composite. Pinning centers were categorized into weak and strong pinning centers. NP-Dy2O3 gives more weight to the strong pinning components. (C) 2020 Elsevier B.V. All rights reserved.