# Scaling of the temperature-dependent resistivity in 122 iron-pnictide superconductors

### Abstract:

In various electron-doped Ba(Fe_{1 − x }Co

_{ x })

_{2}As

_{2}(

*x*= 0–0.3) and hole-doped Ba

_{1 − x }K

_{ x }Fe

_{2}As

_{2}(

*x*= 0–1) members of the 122-iron-pnictide superconductor family, the temperature-dependent resistivity ρ can be scaled into a universal curve. It is found that the ρ(

*T*) dependences can be reproduced by the formulae &\rho (T)=\rho_0+cT\exp (-\frac {2\Delta }{T}) ; and &\rho (T)=\rho_0+(c/T)\exp (-\frac {2\Delta }{T}) ; in the case of electron and hole doping, respectively. The scaling was performed using the energy scale 2Δ,

*c*and the residual resistivity ρ

_{0}as scaling parameters. The scaling parameters have been calculated and the compositional variation of 2Δ and ρ

_{0}has been determined. The existence of universal metallic ρ(

*T*) curves in Ba(Fe

_{1 − x }Co

_{ x })

_{2}As

_{2}(

*x*= 0–0.3) and Ba

_{1 − x }K

_{ x }Fe

_{2}As

_{2}(

*x*= 0–1) is interpreted as an indication of a single mechanism in each compound which dominates the different scattering of the charge carriers in both compounds. Thus, the scaling of the normal state properties seems to be a general feature not only for high-

*T*

_{c}cuprates but also for the iron-pnictides superconductor family in both under- and overdoped regimes.

**Document Type:** Research Article

**DOI:** https://doi.org/10.1088/0953-2048/24/10/105004

Publication date: October 1, 2011