Bulk Y-Ba-Cu-O superconductors have significant potential for engineering applications due to high critical current density (Jc) and high trapped magnetic fields, which is attributed to the presence of pinning centers such as micro-sized Y2BaCuO5 (Y211) inclusions. The introduction of nanosized particles is known to function as more effective pinning centers than micro-sized ones. It has been reported that Jc values were enhanced with the addition of nanosized particles such as ZrO2 and Y2Ba4CuMOy (M = Nb, Zr, etc.) in the YBa2Cu3Ox (Y123) matrix. We have focused on nanocarbon as another candidate of the pinning center and reported that the addition of carbon nanotube (CNT) and nanodiamond led to the enhancement of Jc in Y-Ba-Cu-O superconductors. Fullerene (C60) is also expected to improve the flux pinning performance. We then fabricated melt-processed Y-Ba-Cu-O bulk samples with the addition of fullerene and investigated the pinning properties and microstructures. SEM observation showed that nanosized particles were distributed in the Y123 matrix. Jc exhibited the highest values for the sample with 1.0 wt% fullerene addition. These results suggest that fullerenes act as effective pinning centers.
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