Fl. Tang et al., STUDY ON PROPERTIES AND MICROSTRUCTURE OF YBA2CU3O7-DELTA-AG-X COMPOSITE SUPERCONDUCTORS PREPARED BY SOL-GEL METHOD, Journal of Materials Science, 30(2), 1995, pp. 347-352
The relation between the microstructure and properties of YBa2Cu3O7-de
lta-Ag-x composite superconductors prepared via sol-gel processing has
been studied. Optical microscopy, SEM and TEM analyses indicated that
Ag-doped samples were dense, with small and regular grains and narrow
spaces between grains. Ag particles were distributed homogeneously in
samples and these could increase their J(0) values. The mechanisms of
the effect of Ag doping on the superconducting properties and microst
ructure of samples were hindrance of the movements of grain boundaries
and metallization of grain boundaries. However, too much Ag doping wo
uld weaken the coupling among superconducting grains and induce J(0) t
o decrease. The experimental results confirmed these ideas.