Scaling of the temperature-dependent resistivity in SrFe2−xNixAs2

We show that the zero-field normal-state resistivity of temperature-dependent resistivity ρ(T) of SrFe2−xNixAs2 can be reproduced by the expression ρ(T) = ρ0 + cT exp(−2Δ/T). ρ(T) can be scaled using both this expression where the energy scale Δ, c and the residual resistivity ρ0 are scaling parameters and a recently proposed model-independent scaling method (H.G. Luo, Y.H. Su, T. Xiang, Phys. Rev. B 77 (2008) 014529). The scaling parameters have been calculated and the compositional variation of 2Δ(x) has been determined. This dependence show almost a linear decreasing in the underdoped regime similar to that reported for cuprates. The existence of a universal metallic ρ(T) curve in a wide temperature range which, however, is restricted for the underdoped compounds to temperatures above a structural and anitiferromagnetic transition is interpreted as an indication of a single mechanism which dominates the scattering of the charge carriers in SrFe2−xNixAs2 (x = 0–0.3).

► The normal-state resistivity of SrFe2-xNixAs2 (x = 0–0.3) single crystals is analyzed. ► The resistivity exhibits good scaling behavior for all compositions. ► A single charge carriers scattering mechanism dominates in SrFe2-xNixAs2 (x = 0–0.3).