The Effect of Silver Inclusion on Superconducting Properties of YBa2Cu3O y Prepared Using Planetary Ball Milling

Abstract

The effect of Ag inclusion on the structure microstructure and the critical current density of the YBa2Cu3O7−δ sample prepared using the planetary ball milling process has been investigated. YBa2Cu3O7−δ ceramics have been synthesized in air by a solid state reaction method from an oxide precursor powder, which was prepared from the starting powders of Y2O3, Ba2CO3, and CuO via a one-step annealing process in air at 950 ∘C. After planetary ball milling for 4 h of the oxide precursor powders, it was mixed with an AgNO3 solution, and then was dried and uniaxially pressed, and subsequently annealed at 950 ∘C in air. Phase analysis by X-ray diffraction (XRD), granular structure examination by scanning electron microscopy (SEM), microstructure investigation by transmission electron microscopy (TEM) coupled with energy dispersive X-ray spectroscopy (EDXS) were carried out. To understand the effects of the ball milling on the pinning behavior, magnetic field and temperature dependences on a critical current density have been studied. Analyses show that Ag-milled YBCO samples exhibit higher values of critical current density in applied magnetic field compared to Ag-unmilled one. The better pinning properties of the Ag-milled samples are believed to be due to the microstructure of more fine and uniform distribution of silver and Y-deficient nanosized generated by ball milling.