In present work, we have studied the effect of nano-crystalline Cu (na
no-Cu) addition on properties of the bulk YBa2Cu3O7-delta superconduct
ors. The results reveal that the T-c does not vary with the nano-Cu co
ntent. However, the intragranular critical density J(cm) improves due
to nano-Cu addition, which gives evidence that the nano-Cu particles i
ntroduced into superconducting matrix take the role of effective flux
pinning centers.