External and internal diffusion of oxygen in superconducting YBa/sub 2/Cu/sub 3/O/sub 7/ composite conductors

They report a systematic investigation of the critical current at 77K for a number of different composite conductors based on the high critical temperature superconductor YBa/sub 2/Cu/sub 3/O/sub 7/. Results are reported for an 'external' diffusion composite where the oxygen diffuses through an outer cladding of silver, and for an 'internal' diffusion design where the composite is clad externally with an oxygen impermeable layer and oxygen diffuses internally from a channel within the conductor. Measurements are reported of the dependence of the critical current on i) the preparation route for the superconducting powder, ii) the preform particle size, iii) the presence of air or vacuum during compaction, iv) the time of the sintering anneal and v) the applied load on the conductor during a critical current test