BaZrO₃ (BZO) nanoparticles as effective pinning centers for YBa₂Cu₃O_7 − δ (YBCO) superconducting thin films

In-field pinning enhancement for high temperature YBCO superconducting thin film is one of the most significant issue towards future high field applications. Various pinning nanostructures have been designed to achieve better superconducting performance. In this work, BaZrO₃ (BZO) has been introduced into YBCO for pinning enhancement. Small BZO nanoparticles with diameter of ~ 5 nm have been observed in the YBCO matrix with high film quality. The BZO-YBCO film deposited at 840 °C exhibits the highest transition temperature of 90 K. These small nanoparticles can provide effective pinning centers for the superconducting property enhancement of YBCO. By comparing the critical current density (Jc) performance of YBCO films, with or without incorporating BZO nanoparticles, 840 °C deposited BZO-YBCO exhibits obvious higher Jc values of 7.8 MA/cm², 26.5 MA/cm² and 64.5 MA/cm² at the measured temperatures of 65 K, 40 K and 5 K, respectively. The results indicate an effective approach to achieve enhanced in-field performance of YBCO, by introducing small BZO nanoparticles.