Investigation of the Flux Pinning Properties of YBCO/NaNbO3 Nanoparticle Composite Superconductor

In the present work, we are reporting the impact of addition of sodium niobate (NaNbO3) nanoparticles (NPs) on the flux pinning properties of YBCO compound with different wt% (0 to 2%) of NaNbO3. The structural analysis reveals that the orthorhombic crystal structure of YBCO remains unchanged in the nanocomposite samples. The presence of NaNbO3 in the YBCO nanocomposites is confirmed by elemental analysis technique. No significant change in the superconducting transition temperature is observed on addition of NaNbO3 NPs in YBCO compound for up to 2 wt% concentration. Magnetization hysteresis loop measurement indicates a significant enhancement in the value of critical current (J(C)) and pinning force (F-P) in the YBCO/x NaNbO3 (NP) composite samples which is attributed to the generation of sufficient no. of defect centers in YBCO matrix due to addition of NPs of NaNbO3. At lower fields and temperature range 10-60 K, the 0.5 wt% NP-added composite sample has shown maximum enhancement in J(C) whereas at higher temperatures and higher fields, the maximum improvement in the pinning properties is observed for 0.25 wt% NaNbO3-added YBCO sample.