Abstract:
Utilization of novel materials, particularly high-
Tc (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
2Cu
3O
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
3Cu
5O
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
Tc of approximately 90 K. However, in the samples cut from the bottom surface, the onset
Tc 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
Jc (critical current density) at 77 K
H//
c-axis of 50 and 55 kA/cm
2, respectively. The remnant
Jc and irreversibility field values significantly fluctuated, being fairly low in some bottom samples. Scanning electron microscopy identified nanometer size Y-211 (Y
2BaCuO
5) secondary-phase particles dispersed in the Y-123 matrix. Energy-dispersive spectroscopy clarified that the decreased both
Tc and
Jc for the bottom samples were attributed to liquid phase dispersion within the Y-123 phase.