Résumé | The solid-state reaction between nickel and YBa₂Cu₃Oₓ was studied by hot isostatic pressing of YBa₂Cu₃Oₓ green compacts in nickel. The microstructure, density and nature of phases present in hot isostatically pressed (HIP) parts were characterised. Resistivity measurements indicated that HIP parts are not superconducting owing to the loss of oxygen and required an annealing step in oxygen for restoring superconductivity. The diffusion of nickel into YBa₂Cu₃Oₓ as well as the diffusion of Ba, Cu and Y into nickel was very limited. However, a thin interaction zone consisting of a nickel-rich oxide compound was formed at the Ni-YBa₂Cu₃Oₓ interface. The presence of such an interaction zone could have a detrimental effect on the thermal stabilisation of Ni-YBa₂Cu₃Oₓ composite wires. |
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