The study of inter and intragranular pinning behavior of oxygen irradiated textured polycrystalline Bi2Sr2CaCu2O<f>8+δ</f> and Bi1.84Pb0.34Sr1.91Ca2.03Cu3.06O<f>10+δ</f> superconductors

Inter and intragranular pinning potentials of 116 MeV oxygen ion irradiated textured polycrystalline Bi2Sr2CaCu2O<f>8+δ</f> (Bi-2212) and Bi1.84Pb0.34Sr1.91Ca2.03Cu3.06O<f>10+δ</f> (Bi-2223) have been studied from dc magnetization at low (50 Oe) and high (10,000 Oe) fields respectively. There is an increase in intergranular pinning potential <f>(U0)</f> in Bi-2223 in contrast to anomalous decreases in Bi-2212 with increasing dislocation density. Intragranular pinning potential is governed by the concentration of vacancy type defects rather than its size as observed in proton irradiation. Pinning has been explained in the light of statistical dilute pinning model. [Copyright &y& Elsevier]