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Microstructural Development and Superconducting Parameters of the YBa2Cu3O7-delta Coated Conductor 10.17863/CAM.14203 Rutter, Noel Anthony A coated conductor is generally fabricated by depositing a high Tc superconducting layer onto a flexible metallic substrate, using intermediate buffer layers to prevent chemical interaction. In order for the superconductor to be capable of carrying a high current density, its grains must have good crystallographic alignment in order to avoid the presence of high angle grain boundaries. This can be ensured by transferring the texture from the substrate through epitaxial film growth. The main substrate considered in this thesis is a Ni-Fe alloy. When cold-rolled, NiFe develops a preferential orientation and upon annealing at an elevated temperature, undergoes primary recrystallisation to form grains with the cube texture {100}<001>. The recrystallisation process and the texture of the tapes has been examined and various buffer layers have been fabricated. As silver does not react adversely with high temperature superconductors, it has been deposited onto Pd-buffered NiFe by DC sputtering and very sharp cube texture is obtained. Ceramic buffer layers, CeO2 and YSZ, have been deposited by RF sputtering, though an undesirable (111) oriented component accompanies the cube textured material. Also a technique has been developed to produce a suitably oriented native oxide of NiFe by a simple oxidation technique. Preliminary attempts to deposit YBCO films onto these buffer layers have shown that the quality of the metallic buffers is degraded by rapid inter-diffusion at elevated temperatures, but that cube textured material can be deposited on the oxide buffer layers. The percolative nature of current flow in such coated conductors has been considered through the development of a grain network model. As the texture of the superconducting layer is directly influenced by the underlying layers, measurements from the substrate and buffer layers are applied in order to model the orientations of the grains in a superconducting overlayer. The model calculates the critical current of coated conductors as a function of parameters such as length, width, grain size and texture, as well as examining factors such as cracks and highly misoriented grains. University of Cambridge 2001 Thesis Doctoral Doctor of Philosophy (PhD) en EPSRC http://www.dspace.cam.ac.uk/handle/1810/34597 https://www.repository.cam.ac.uk/handle/1810/34597 https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/b7994834-2a06-4e29-9b7f-eee917a00cf0/download 68ea4ee32890c60caaa73c8e5352cdf1 https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/cfa908ba-55c7-42f2-b173-3e769203965f/download 2639edfb76d9db030b32c74909396ebd https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/9fc7eb42-dc58-4916-8553-aa9207feb668/download 7ead18eac778fa1cfe6d17ce9025e055 https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/3e55b63c-adb5-4872-be49-ce1b82a3318e/download bc9bea0295db6bbf6a63321b93c1c489 https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/5950a5b5-72cd-4102-855b-401656438ca5/download e6336f9034ac85ea3db779c01c86a292 https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/0a28b06a-ab65-47a5-8f13-197372801d4a/download cf792ab3afd2a0a1d8d4df14d967ab71 https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/077db5bb-b67d-4bb3-9647-404372d1f7e4/download 3cc4c019fe3c025b8bda2cb26b29d65b https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/2e11dc59-fd70-4c52-b4bf-7590576dcfae/download 6bb2f644f9aedcc52b1409f70183f59d https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/8c1a3f76-a72f-420e-93ef-bf51408a4682/download 68c37c299e52c349968c00d580ed6a75 https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/c95f3956-9fd1-451d-b5d3-6a99a250d082/download 77bfefb32c151a61745cff94f345eb88 https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/24f88fc4-3ef3-473b-8be8-cb099c0fe4b2/download 80fd7b68a7a93abb95d1a9b483ba17cb https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/75fadd6b-ea2f-4fd5-b444-dde783414796/download b4402782a8fe9a167bc029366fd7befc https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/33e78d64-2953-4b36-89fe-d87f404a9b80/download d76aca2544e19c75e3d7d8af9d9786f9 https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/7ef3bc33-3536-4e62-ac4a-7f071c650993/download 353d3206403502020208d3e8db80571d https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/cd656158-5c05-4adf-baea-a8d968c68f74/download f2d5253abf9748235b06ca5c842f0ba6 https://www.rioxx.net/licenses/all-rights-reserved/ YBCO Coated Conductor Percolation Microstructure