Utilization of novel materials,particularly high-T_(c)(critical temperature)superconductors,is essential to pursue the United Nations’Sustainable Goals,as well as to meet the increasing worldwide demand for clean and...Utilization of novel materials,particularly high-T_(c)(critical temperature)superconductors,is essential to pursue the United Nations’Sustainable Goals,as well as to meet the increasing worldwide demand for clean and carbon-free electric power technologies.Superconducting magnets are beneficial in several real-life applications including transportation,energy production,magnetic resonance imaging(MRI),and drug delivery systems.To achieve high performance,one must develop uniform,large-grain,infiltration-growth(IG)processed bulk YBa_(2)Cu_(3)O_(y)(Y-123)super-magnets.In this study,we report the magnetic and microstructural properties of a large-grain,top-seeded,IG-processed Y-123 pellet,which is 20 mm in diameter and 6 mm in height;the pellet is produced utilizing liquid Yb-123+Ba_(3)Cu_(5)O_(8) as the liquid source.All the samples cut from the top of the bulk exhibit a sharp superconducting transition(approximately 1 K wide)with the onset T_(c) of approximately 90 K.However,in the samples cut from the bottom surface,the onset T_(c) values slightly decreased to between 88 and 90 K,although still exhibiting a sharp superconducting transition.The top and bottom samples exhibited the highest remnant value of J_(c)(critical current density)at 77 K H//c-axis of 50 and 55 kA/cm^(2),respectively.The remnant J_(c) and irreversibility field values significantly fluctuated,being fairly low in some bottom samples.Scanning electron microscopy identified nanometer size Y-211(Y2BaCuO5)secondary-phase particles dispersed in the Y-123 matrix.Energy-dispersive spectroscopy clarified that the decreased both T_(c) and J_(c) for the bottom samples were attributed to liquid phase dispersion within the Y-123 phase.展开更多
基金This work was presented at the International Conference on Carbon Materials and Nanotechnology,Osaka,Japan(JICCMAN 2020)which was held during June 30–July 1 of 2020 as an online summit.This work was delivered as an oral presentation and was acknowledged with the Outstanding Young Researcher Award.
文摘Utilization of novel materials,particularly high-T_(c)(critical temperature)superconductors,is essential to pursue the United Nations’Sustainable Goals,as well as to meet the increasing worldwide demand for clean and carbon-free electric power technologies.Superconducting magnets are beneficial in several real-life applications including transportation,energy production,magnetic resonance imaging(MRI),and drug delivery systems.To achieve high performance,one must develop uniform,large-grain,infiltration-growth(IG)processed bulk YBa_(2)Cu_(3)O_(y)(Y-123)super-magnets.In this study,we report the magnetic and microstructural properties of a large-grain,top-seeded,IG-processed Y-123 pellet,which is 20 mm in diameter and 6 mm in height;the pellet is produced utilizing liquid Yb-123+Ba_(3)Cu_(5)O_(8) as the liquid source.All the samples cut from the top of the bulk exhibit a sharp superconducting transition(approximately 1 K wide)with the onset T_(c) of approximately 90 K.However,in the samples cut from the bottom surface,the onset T_(c) values slightly decreased to between 88 and 90 K,although still exhibiting a sharp superconducting transition.The top and bottom samples exhibited the highest remnant value of J_(c)(critical current density)at 77 K H//c-axis of 50 and 55 kA/cm^(2),respectively.The remnant J_(c) and irreversibility field values significantly fluctuated,being fairly low in some bottom samples.Scanning electron microscopy identified nanometer size Y-211(Y2BaCuO5)secondary-phase particles dispersed in the Y-123 matrix.Energy-dispersive spectroscopy clarified that the decreased both T_(c) and J_(c) for the bottom samples were attributed to liquid phase dispersion within the Y-123 phase.
