A Modular Ex Situ Conversion Process for Thick MOD-Fluoride RBCO Precursors

Following a review of heating induced chemical and structural changes in RBa
₂
Cu
₃
O
₇
(RBCO) fluoride precursors (R = rare earth of Y) deposited by metalorganic deposition (MOD) and physical vapor deposition (PVD), a modular process comprising successive, functionally distinct, brief annealing steps (modules) is introduced. By decoupling events that otherwise occur simultaneously, the modular process provides a framework for addressing the complex kinetics associated with the temperature ramp of the
ex

situ
conversion anneal. Modules for modifying the F concentration, porosity and microstructure, and RBCO nucleation are described.