Abstract
The combined effect of the addition of different weight percentages of nano-BaTiO3/WO3 particles, synthesized through a solid-state reaction route in bulk YBCO superconductor was studied. The examination by X-ray diffraction (XRD) showed that the samples crystallize into the orthorhombic structure. The orthorhombic distortion reduced with increasing the content of BTO and WO3 nanoparticles. The diminution of the orthorhombic distortion is followed by a significant alteration of critical transition temperature (T-co) at high addition level. The variation in crystallite size, electrical transport, magnetic field dependence of critical current density (J(c)), and flux-pinning force (F-p) of YBCO with various amounts of BTO, WO3 nanoparticles were studied in detail. The self-field critical current density (J(c)) increases to a maximum value of 0.32 x 10(4) A cm(-2) for the 0.05 wt% co-addition of nano-BTO/WO3 particles. The factor boosting in this content was found to reach up to 45 when compared to the pure sample in the entire applied magnetic field. The enhancement of J(c) values in the 0.05 wt% added sample was attributed to the presence of high-efficiency crystal defects that act as artificial pinning centers, formed due to the BTO/WO3 nanoparticles co-addition. Also, the pinning force density was enhanced by the co-addition of nano-BTO/WO3 particles in YBCO bulk superconductor and attained a maximum value of 1.5 MT.A.m(-2) at 77 K for x = 0.05 wt%.