Some effects of the doping with alpha - Al_2O_3 nanoparticles in the transport properties of Bi_1.65 Pb_0.35 Sr_2Ca_2 Cu_3O_y ceramic superconductors

Abstract

We present a preliminary study on the effects of alpha - Al_2O_3 nanoparticles (NPs) in the transport properties of Bi_1.65 Pb_0.35 Sr_2Ca_2 Cu_3O_y ((Bi,Pb)-2223) ceramic samples. The (Bi,Pb)-2223 samples were synthesized by the solid state reaction method and alpha - Al_2O_3 NPs, with concentrations ranging from 0.1 to 0.8 wt. percent (% wt.), were added before the last heat treatment. All samples were characterized by means of X-rays diraction patterns, and temperature and magnetic eld dependence of the electrical resistivity, rho(T;Ba). From the experimental (T;Ba) data we extracted the critical temperature dependence of the % wt. of alpha - Al_2O_3 NPs, and by using the Arrheniusplot the eective pinning energy has been also determined. The results indicate that mostly of the transport properties are optimized for the sample B03.