Codoping Effect of Zn and Pr in YBa2Cu3O7-δ

M.S. Naik, P.R. Sarode, R.B. Prabhu, K.R. Priolkar Department of Physics, Goa University, Taleigao Plateau, Goa 403 206, India

and N.Y. Vasanthacharya Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560 012, India

Received: October 10, 2008; Revised version: December 12, 2008;

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In this paper we present the resistivity data for Pr and Zn codoped compound Y1-xPrxBa2[Cu1- yZny]3O7-δ with 0 < y < 0.1 and x=0.0, 0.1 and 0.2. The data is analysed in terms of the superconducting critical temperature Tc, residual resistivity ρ0 and the resistivity slope dρ/dT corresponding to the linear ρ-T region. It is found that for x=0.1 Pr has a minimal influence on the in-plane processes for Zn impurity alone affecting slightly Tc and ρ0. The slope dρ/dT becomes larger for 0.03 < y < 0.06 leading to larger depining effect and hence slower fall of Tc as a function of y. For x = 0.2 there is a drastic change, ρ0 becomes abnormally large, dρ/dT becomes negative implying absence of depinning and a totally pinned charge stripes. Superconductivity vanishes at y=0.03. It is concluded that for x = 0.2 Pr converts the system from overdoped to underdoped region leading to the universal superconductor-insulator transition.

DOI: 10.12693/APhysPolA.115.742 PACS numbers: 74.62.Bf, 74.62.Dh, 74.72.Bk