Activation energy and excess conductivity analysis of (Ag)(x)/CuTl-1223 nano-superconductor composites

作者：Hussain Ghulam; Jabbar Abdul; Qasim Irfan; Mumtaz M^*; Nadeem K; Zubair M; Abbas S Qamar; Khurram A A

来源：Journal of Applied Physics, 2014, 116(10): 103911.

DOI：10.1063/1.4895051

Silver (Ag) nanoparticles were added into (Cu0.5Tl0.5)Ba2Ca2Cu3O10-delta (CuTl-1223) high T-c superconducting matrix to get (Ag)(x)/CuTl-1223, x = 0, 0.5, 1.0, 2.0, and 4 wt. %, nano-superconductor composites. The activation energy {U (eV)} and zero resistivity critical temperature {T-c (0)} were increased with increasing contents of Ag nanoparticles in (CuTl-1223) phase up to x = 2.0 wt.%. The increase of activation energy is most probably due to interaction of carriers with the metallic Ag nanoparticles present at grain boundaries of the host CuTl-1223 superconducting matrix. The systematic increase in T-c (0) and gradual decrease in normal state resistivity {rho(300K) (Omega cm)} may be due to improved inter-grains coupling by filling up the voids and pores with the inclusion of metallic Ag nanoparticles at the grain-boundaries. There are two possible mechanisms associated with the inclusion of Ag nanoparticles, one is the formation of non-superconducting regions causing the increase of activation energy and other (dominating) is the improved inter-grains connectivity promoting T-c (0). The microscopic parameters (i.e., zero temperature coherence l

• 出版日期2014-9-14