Impurity Effects on the Superconducting Transition Temperature of NazCoO2.yH2O

TL;DR

This study investigates how doping with Ir and Ga affects the superconducting transition temperature in NazCoO2.yH2O, revealing suppression not solely explained by pair breaking, suggesting other mechanisms at play.

Contribution

It provides experimental data on impurity doping effects in NazCoO2.yH2O and discusses potential alternative explanations for Tc suppression beyond pair breaking.

Findings

Tc decreases with impurity doping at about 1 K/%

Pair breaking mechanism does not fully explain Tc suppression

Possible alternative mechanisms are discussed

Abstract

Superconducting transition temperature Tc of NazCo1-xMxO2.yH2O has been studied for M=Ir and Ga, which can substitute for Co. It has been found that Tc is suppressed by the M-atom doping. The decreasing rates |dTc/dx| are of the order of 1 K/% and too small to be explained by the pair breaking mechanism for the anisotropic order parameters by non-magnetic impurities. Brief arguments are given on possible origins of the Tc suppression.