Current Applied Physics, Vol.16, No.10, 1270-1276, 2016
Magneto transport study of YBCO: Ag composites
We study the effect of Ag addition on the magnetoresistance and allied properties of YBCO. We find that the zero resistance temperature (T-C0) shift is narrowed down by the addition of Ag as magnetic field (H) is increased from 0 to 13 T. The resistivity broadening of composites under magnetic field exhibits Arrhenius behavior due to thermally activated flux flow of vortices. The activation energy, determined from Arrhenius plot of resistivity, increases with the addition of Ag in YBCO and is found optimum for 15% Ag composite. The vortex glass transition temperature is found more in YBCO: Ag composites as compared to pristine YBCO. The zero temperature upper critical field H-c2(0) estimated by using Werthamer, Helfand and Hohenberg theory and Ginzburg Landau theory shows two fold enhancement by adding Ag in YBCO matrix. We find that the addition of Ag in YBCO leads to an enhancement in activation energy, an increases in H-c2(0) in addition to better grain connectivity. (C) 2016 Elsevier B.V. All rights reserved.