Effect of Zn doping in under- and over-doped LaFe^sub 1-x^Co^sub x^AsO system

The researchers study the effect of nonmagnetic Zn impurity on superconductivity in the Co-doped LaFe^sub 1^-χ-^sub y^CoχZn^sub y^AsO system. A light Zn doping drastically suppresses the superconducting transition temperature T... 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 T^sub c^ decrease is substantially smaller in the under-doped regime than in the over-doped regime. They propose that the less drastic T^sub c^ reduction in the under-doped superconductor is due to the suppression of a competing antiferromagnetic order, which is in favor of superconductivity. (ProQuest: ... denotes formulae/symbols omitted.)