Abstract
The effect of Ag inclusion on the structure microstructure and the critical current density of the YBa
2
Cu
3
O
7−
δ
sample prepared using the planetary ball milling process has been investigated. YBa
2
Cu
3
O
7−
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 Y
2
O
3
, Ba
2
CO
3
, 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 AgNO
3
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.