Controlled BZO Nanorod Growth and Improved Flux Pinning in YBCO Films Grown on Vicinal STO Substrates

Abstract

<p>The present study systematically investigates the impact of strain-induced defects on the anisotropy of the critical current density across wide temperature and magnetic field ranges. We focus on 0-10 wt % BaZrO₃ (BZO)-doped YBa₂Cu₃O_7-x (YBCO) thin films that are deposited on SrTiO₃ substrates with a 5<strong>°</strong> surface miscut. Our findings highlight the crucial role played by these vicinal substrates in governing the growth of BZO nanorods within the YBCO films. Interestingly, we observe that the miscutinduced surface step-edge terraces serve as preferred nucleation sites for BZO, resulting in controlled nanorod growth and a significant enhancement in both the self-field and in-field critical current densities. Furthermore, we note that the optimal BZO content for effective flux pinning varies considerably depending on the applied temperature, magnetic field, and its orientation. These findings hold significant implications for the design and development of high-performance superconducting materials. The primary objective in such endeavors is to construct an optimal flux pinning structure that can achieve a high critical current density at relatively high magnetic fields.<br></p>