The effects of Nd2O3 nanoparticles addition on microstructure, transport and AC susceptibility properties of YBa2Cu3O7–δ（Y123） superconductors were systematically investigated using X-ray diffraction （XRD）, scan...The effects of Nd2O3 nanoparticles addition on microstructure, transport and AC susceptibility properties of YBa2Cu3O7–δ（Y123） superconductors were systematically investigated using X-ray diffraction （XRD）, scanning electron micrograph （SEM）, four point probe measurement and AC spectrometer. It was found that the added samples were predominant by Y-123 phase beside small amount of Y-211 and unreacted Nd2O3secondary phases. All added samples preserved the orthorhombic structure similar to the pure sample and no orthorhombic-to-tetragonal transition occurred. The samples became more porous and their grain size significantly de-creased with addition of Nd2O3. The addition of nano-Nd2O3 disturbed the grain growth of Y123, thus resulting in the degradation of superconducting properties of the samples. The superconducting transition temperature （Tc onset） of samples decreased from 92 K for x=0.0 to 78 K forx=1.0 wt.%, which could be attributable to oxygen vacancy disorder. From AC susceptibility result, the inter- and intra-granular loss peaks became wider and broader with increase of Nd2O3 addition due to the weakening of grains coupling. On the other hand, the inter-granular critical current density,Jcm, was found to increase with Nd2O3 addition and had the highest value at x=0.6, confirming that Nd2O3 nanoparticles acted as pinning centers in Y123 matrix.展开更多
基金Project supported by Exploratory Research Grants Scheme(ERGS)(5527047)University Putra Malaysia through the Putra Grant(9440100)Ministry of Education Malaysia(MOE)and University Malaysia Terengganu(UMT)
文摘The effects of Nd2O3 nanoparticles addition on microstructure, transport and AC susceptibility properties of YBa2Cu3O7–δ（Y123） superconductors were systematically investigated using X-ray diffraction （XRD）, scanning electron micrograph （SEM）, four point probe measurement and AC spectrometer. It was found that the added samples were predominant by Y-123 phase beside small amount of Y-211 and unreacted Nd2O3secondary phases. All added samples preserved the orthorhombic structure similar to the pure sample and no orthorhombic-to-tetragonal transition occurred. The samples became more porous and their grain size significantly de-creased with addition of Nd2O3. The addition of nano-Nd2O3 disturbed the grain growth of Y123, thus resulting in the degradation of superconducting properties of the samples. The superconducting transition temperature （Tc onset） of samples decreased from 92 K for x=0.0 to 78 K forx=1.0 wt.%, which could be attributable to oxygen vacancy disorder. From AC susceptibility result, the inter- and intra-granular loss peaks became wider and broader with increase of Nd2O3 addition due to the weakening of grains coupling. On the other hand, the inter-granular critical current density,Jcm, was found to increase with Nd2O3 addition and had the highest value at x=0.6, confirming that Nd2O3 nanoparticles acted as pinning centers in Y123 matrix.
