Enhanced Critical Current Density and Flux Pinning in KNbO3: YBCO Nanocomposite Thin Films

In this study, we detail the KNbO₃:YBCO film deposition process using the pulsed laser deposition (PLD) technique and explore the influence of potassium niobate (KNbO₃) nanoparticles (NPs) on pinning characteristics of nanocomposite YBCO films. The XRD investigation confirms the orthorhombic phase of YBCO, and it remains consistent even when NPs are included in the nanocomposites. A Magnetic Property Measurement System (MPMS) is used to measure the magnetic characteristics, applying a field within a range of ± 7 T. The KNbO₃:YBCO nanocomposite thin films exhibit higher critical current (J_c) in comparison to YBCO films. Notably, the most substantial improvement, ~ 3.5-fold, in J_c and flux pinning properties is observed in 0.5 wt% KNbO₃:YBCO nanocomposite thin films. Furthermore, the investigation reveals that nanocomposite films display a slower rate of J_c decay with the increase of fields as compared to YBCO thin films, indicating improved pinning properties. The results indicate that introducing small KNbO₃ nanoparticles in YBCO matrix is an effective way to enhance the in-field performance of YBCO.