Angular dependence of the high-frequency vortex response in YBa2Cu3O7―x thin film with self-assembled BaZrO3 nanorods

• Published in: Physica. C, Superconductivity Vol. 479; pp. 160 - 163
• Main Authors: POMPEO, N, ROGAI, R, TOROKHTII, K, AUGIERI, A, CELENTANO, G, GALLUZZI, V, SILVA, E
• Format: Conference Proceeding Journal Article
• Language: English
• Published: Amsterdam Elsevier 01-09-2012
• Subjects: Anisotropy; Condensed matter: electronic structure, electrical, magnetic, and optical properties; COPPER OXIDE; Exact sciences and technology; FLUID FLOW; FREQUENCY; High-tc films; MATHEMATICAL ANALYSIS; Mathematical models; Nanorods; Physics; Pinning; Properties of type I and type II superconductors; ROD; Superconducting films and low-dimensional structures; Superconductivity; SUPERCONDUCTORS; THIN FILMS; Vortex lattices ,flux pinning, flux creep; Vortices; YBCO superconductors; YTTRIUM OXIDE; Superconducting thin films; Surface impedance; Barium Zirconates; Angular dependence; nanorods; Microwave radiation; Self-assembled layers; Vortex dynamics; Nanocomposites; Anisotropy; Vortices; Scaling laws; High-Tc superconductors; BaZrO; Vortex motion; Angular variation; High frequency; YBCO; Nanorod; Barium Copper Yttrium Oxides Mixed
• ISSN: 0921-4534; 1873-2143
• DOI: 10.1016/j.physc.2011.12.008

We present a microwave study of the angular dependence of the flux-flow resistivity ?ff and of the pinning constant kp in YBCO thin films containing BZO nanorods. We find that BZO nanorods are very efficient pinning centers, even in tilted fields. We find that ?ff is a scaling function of a reduced field H/f(?). We extend a model for the anisotropic motion of vortices in uniaxially anisotropic superconductor, able to describe the experimental f(?) on the basis of only the intrinsic anisotropy of YBCO. The pinning constant kp, by contrast, exhibits different field dependences in different angular ranges, consistent with pinning by BZO at angles as large as 60 degree , and with pinning along the a,b planes as originating from the same mechanism as in pure YBCO with the field along the c axis.