High quality GdBa2Cu307-y （Gd123） textured bulks with Nd2BaCuO5 （Nd211） nanoparticle precipitations have been fabricated by a nanoparticle-powders-assisted MTG （melt-textured-growth） technique. The high density ...High quality GdBa2Cu307-y （Gd123） textured bulks with Nd2BaCuO5 （Nd211） nanoparticle precipitations have been fabricated by a nanoparticle-powders-assisted MTG （melt-textured-growth） technique. The high density nanoscale flux pinning sites were introduced into Gd123 by mixing Nd211 nanoparticle powders （about 20-50 nm） with Gd123 nano-precursors before the MTG process. Microstructural analyses reveal that a large number of Nd211 nanoparticles with a size around 50-150 nm were inserted in the Gd123 matrix, forming a kind of superconducting nanocomposites. The critical current density at 77 K is systematically increased and the flux pinning behavior is significantly improved. The scaling behavior of the flux pinning force shows a magnetic field dependent feature with a peak located at hp≈0.4. This may be the fingerprint of melt-textured 123 compounds, which cannot be interpreted by the simple superposition of different types of elementary pinning sources.展开更多
基金supported in part by the National Natural Science Foundation of China (No. 50872116)the Fundamental Research Funds for the Central Universities of China (No. SWJTU09ZT24)+1 种基金the PCSIRT of the Ministry of Education of China (No.IRT0751)the Specialized Research Fund for the Doctoral Program of Higher Education of China (No. 200806130023)
文摘High quality GdBa2Cu307-y （Gd123） textured bulks with Nd2BaCuO5 （Nd211） nanoparticle precipitations have been fabricated by a nanoparticle-powders-assisted MTG （melt-textured-growth） technique. The high density nanoscale flux pinning sites were introduced into Gd123 by mixing Nd211 nanoparticle powders （about 20-50 nm） with Gd123 nano-precursors before the MTG process. Microstructural analyses reveal that a large number of Nd211 nanoparticles with a size around 50-150 nm were inserted in the Gd123 matrix, forming a kind of superconducting nanocomposites. The critical current density at 77 K is systematically increased and the flux pinning behavior is significantly improved. The scaling behavior of the flux pinning force shows a magnetic field dependent feature with a peak located at hp≈0.4. This may be the fingerprint of melt-textured 123 compounds, which cannot be interpreted by the simple superposition of different types of elementary pinning sources.
