Articles by Alexei E. Koshelev in JoVE
High-resolution Thermal Micro-imaging Using Europium Chelate Luminescent Coatings Timothy M. Benseman1,2,3, Yang Hao1,2, Vitalii K. Vlasko-Vlasov1, Ulrich Welp1, Alexei E. Koshelev1, Wai-Kwong Kwok1, Ralu Divan4, Courtney Keiser5, Chiharu Watanabe6, Kazuo Kadowaki6 1Materials Science Division, Argonne National Laboratory, 2Department of Physics, University of Illinois at Chicago, 3Department of Physics, CUNY Queens College, 4Center for Nanoscale Materials, Argonne National Laboratory, 5Department of Physics, University of Northern Iowa, 6Institute for Materials Science, University of Tsukuba Europium thenoyltrifluoroacetonate (EuTFC) has an optical luminescence line at 612 nm, whose activation efficiency decreases strongly with temperature. If a sample coated with a thin film of this material is micro-imaged, the 612 nm luminescent response intensity may be converted into a direct map of sample surface temperature.
Other articles by Alexei E. Koshelev on PubMed
Toward Superconducting Critical Current by Design Advanced Materials (Deerfield Beach, Fla.). Jun, 2016 | Pubmed ID: 27030115 A new critical-current-by-design paradigm is presented. It aims at predicting the optimal defect landscape in superconductors for targeted applications by elucidating the vortex dynamics responsible for the bulk critical current. To this end, critical current measurements on commercial high-temperature superconductors are combined with large-scale time-dependent Ginzburg-Landau simulations of vortex dynamics.
Vortices in High-performance High-temperature Superconductors Reports on Progress in Physics. Physical Society (Great Britain). Nov, 2016 | Pubmed ID: 27652716 The behavior of vortex matter in high-temperature superconductors (HTS) controls the entire electromagnetic response of the material, including its current carrying capacity. Here, we review the basic concepts of vortex pinning and its application to a complex mixed pinning landscape to enhance the critical current and to reduce its anisotropy. We focus on recent scientific advances that have resulted in large enhancements of the in-field critical current in state-of-the-art second generation (2G) YBCO coated conductors and on the prospect of an isotropic, high-critical current superconductor in the iron-based superconductors. Lastly, we discuss an emerging new paradigm of critical current by design-a drive to achieve a quantitative correlation between the observed critical current density and mesoscale mixed pinning landscapes by using realistic input parameters in an innovative and powerful large-scale time dependent Ginzburg-Landau approach to simulating vortex dynamics.