Efficiency of dysprosium oxide nanoparticles on the intergranular coupling and intragranular properties of YBa2Cu3O7−δ ceramics

The inclusion of a foreign nanostructure phase into the high-temperature superconductor (HTS) materials is a powerful way to generate different effective defects enabling to trap the vortices in different regions of temperature-magnetic field space and upgrading the property of flux pinning. The significant impact of the chemical additives on the traits of superconductor ceramics relies heavily on the concentration, electrical, and magnetic character of the additive. This present paper reported the results of the structural, morphological, and current transport analyses of ( Y 123 ) superconductors added with nanoparticles (Dy 2 O 3 -NPs). Bulk ceramics with porosity around 20% having a nominal composition ( x = 0.0, 0.1, 0.2, and 0.5 wt%) were prepared via the solid-state reaction method. Intragranular critical current density, , was evaluated using DC magnetization measurements. AC susceptibility versus temperature measurements were executed in different AC field amplitudes ( H AC ) at a fixed frequency (1 kHz) and at fixed field amplitude ( H AC = 2 Oe) for various frequencies ranging from 1 to 10 kHz. The volume fraction of superconductor grain ( f sg ), intergranular critical current density ( J c gb ) and activation energy ( E a ) were extracted and discussed. Dy 2 O 3 -NPs added bulk ceramics showed prominent improvement in both intragranular and intergranular superconducting critical parameters. The incorporated Dy 2 O 3 -NPs within the YBCO matrix and the generated defects serve to hinder the motion of vortices and contribute to pinning them. Also, Dy 2 O 3 -NPs setting at the edges of grains could enhance the character of the grain boundaries and takes part in the improvement of connectivity. Within the measured magnetic field window, the addition of 0.2 wt% Dy 2 O 3 -NPs in bulk ceramic resulted in an increase of more than 3.5 times in J c in at an applied magnetic field of 1 T and about 12 times in and strengthen the energy of the cores which nail the vortex by more than 3 times as compared to Y 123 . This finding could be interesting for second-generation HTS technologies such as for fault current limiters and power transmission applications.