Anota Ijaduola, Ph.D.
Area(s) of Expertise: High-temperature superconductors
Education
- Ph.D., University of Tennessee
Research/Special Interests
Dr. Ijaduola's research interests are in the general area of magnetism and superconductivity. In particular, she is interested in the experimental study, characterization and application of magnetic and superconducting materials. To date, most of the work Dr. Ijaduola has done has used a SQUID-based magnetometer as this offers both high sensitivity and versatility in magnetic studies.
Since the discovery of high-temperature superconductors (HTSC) nearly two decades ago, huge efforts have been devoted to understanding and modifying their properties. Presently, coated conductors based on YBa2Cu3O7-δ (YBCO) are being developed as second generation HTSC wires. The use of rolling assisted biaxially textured substrates (RABiTS) is one of the methods being used to circumvent the weak link problem encountered in their fabrication process . This RABiTS approach involves depositing YBCO films on well-textured flexible metallic tapes with buffer layers separating the YBCO and the metallic tape. Nickel and several of its alloy series such as Ni-Cr and Ni-W are well suited as the base material for RABiTS applications.
Magnetic studies and characterization of materials.
In investigations of ferromagnetic materials, one topic has been a study of the magnetic and ferromagnetic properties of series of biaxially textured Ni-W materials with various W contents. These materials are important as substrates for the RABiTS coated conductors.
Vortex pinning in type II superconductors
Exposing a type II superconductor to a magnetic field generates vortices, which have to be made immobile (pinned) in order to have significant and useful superconductive current flow through them. Dr. Ijaduola's research efforts have been geared toward a better understanding of the complex problem of vortex pinning and the identification of defects that support the critical current density Jc in these RABiTS- type coated conductors.
Publications
Enhanced flux pinning and critical currents in YBa2Cu3O7-δ films by nanoparticle surface decoration: Extension to coated conductors template, T. Aytug, M. Paranthaman, K. J. Leonard, K. Kim, A. O. Ijaduola, Y. Zhang, E. Turner, J. R. Thompson, and D. K. Christen, J. Appl. Phys. 104, 043906 (2008).
Flux-pinning characteristics as a function of density of columnar defects comprised of self-assembled nanodots and nanorods in epitaxial YBa2Cu3O7-δ films for coated conductor applications, S. Kang, A. Goyal, J. Li, P. Martin, A. O. Ijaduola, J. R. Thompson, and M. Paranthaman, Physica C 457, 41 (2007).
Critical currents of ex-situ YBa2Cu3O7-δ thin films on rolling-assisted biaxially tex- tured substrates: Thickness, field, and temperature dependencies, A. O. Ijaduola, J. R. Thompson, R. Feenstra, D. K. Christen, A. A. Gapud, and X. Song, Phys. Rev. B 73, 134502 (2006).
Magnetism and ferromagnetic loss in Ni-W textured substrates for coated conductors, A. O. Ijaduola, J. R. Thompson, A. Goyal, C. L. H. Thieme, and K. Marken, Physica C 403, 163 (2004).