Improved Flux Pinning in Melt-Textured YBa2Cu3O7 − δ and ErBa2Cu3O7 − δ Through Chemical Additions

The effects of Ce-based additions (CeO2 and BaCeO3) in combination with MgO additions on the magnetic properties of melt-textured YBa2Cu3O7 − δ and ErBa2Cu3O7 − δ have been investigated. The additions lead to improvements in the magnetic properties of both RE-123 compounds compared to samples with either addition alone or with no additions. The Ce–Mg addition combination produces a “peak effect” in the magnetic hysteresis loop without significant Tc degradation. This is postulated to be due to the formation of a new type of pinning center. Both Ce and Mg ions are thought to substitute in the RE-Ba2Cu3O7 − δ lattice, creating defects that produce a “peak effect” in the magnetic hysteresis loop. Mg additions alone lead to a reduced Tc, while Ce additions restore the Tc and enhance the magnitude of the peak.