Effect of Zn doping in under- and over-doped LaFe1−xCoxAsO system
1 Department of Physics, Hangzhou Normal University - Hangzhou 310036, China
2 State Key Lab of Silicon Materials and Department of Physics, Zhejiang University - Hangzhou 310027, China
Received: 11 November 2012
Accepted: 15 April 2013
We study the effect of nonmagnetic Zn impurity on superconductivity in the Co-doped LaFe1−x−yCoxZnyAsO system. A light Zn doping drastically suppresses the superconducting transition temperature for both under- and over-doped superconductors. This is consistent with the theoretical prediction within the scenario of s±-wave or d-wave pairings. The rate of the Tc decrease, , is substantially smaller in the under-doped regime than in the over-doped regime. We propose that the less drastic Tc reduction in the under-doped superconductor is due to the suppression of a competing antiferromagnetic order, which is in favor of superconductivity.
PACS: 74.70.Xa – Pnictides and chalcogenides / 74.25.F- – Transport properties / 74.20.Rp – Pairing symmetries (other than s-wave)
© EPLA, 2013