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Materials Science and Engineering

2008

Dissertations, Theses, and Masters Projects

Articles 1 - 2 of 2

Full-Text Articles in Engineering

Time-Resolved Magnetic Flux And Ac-Current Distributions In Superconducting Yttrium Barium Copper Oxide Thin Films And Multifilaments, Ran Yang Jan 2008

Time-Resolved Magnetic Flux And Ac-Current Distributions In Superconducting Yttrium Barium Copper Oxide Thin Films And Multifilaments, Ran Yang

Dissertations, Theses, and Masters Projects

Time-resolved magneto-optical imaging (TRMOI) technique allows dynamic ac transport measurements on superconductors. The high time and spatial resolutions of the measurements also offer good quantitative data analysis of the MO images. YBa2Cu 3O7-delta (YBCO) was discovered as a high-temperature superconductor (HTSC) which has wide applications due to its high critical temperature of Tc = 91 K, and high critical current density Jc in the order of 106-7 Acm-2. Many of the applications require high ac current load and a high magnetic field. We study the interaction behavior of YBCO thin films in an ac transport current and a dc magnetic …


Synthesis And Field Emission Properties Of Carbon Nanostructures, Kun Hou Jan 2008

Synthesis And Field Emission Properties Of Carbon Nanostructures, Kun Hou

Dissertations, Theses, and Masters Projects

This dissertation focuses on developing carbon nanostructures for application as the electron emissive material in novel back-gated triode field emission devices. The synthesis, characterization, and field emission properties of carbon nanostructures, including 1-D carbon nanofibers (CNF), 2-D carbon nanosheets (CNS), and chromium oxide coated carbon nanosheets (CrOx-CNS), are presented in this work.;First, we have fabricated aligned carbon nanofiber based back-gated triode field emission devices and confirmed the operation of these devices. 1-D carbon nanofibers were directly synthesized on blank TiW substrates using direct current plasma enhanced chemical vapor deposition. It was found that the morphology of carbon nanofibers could be …