Magnetotransport studies of optimally doped Sr(Fe1-x Co x )2As2

Abstract

We report magnetotransport measurements and their scaling analysis for the optimally electron-doped Sr(Fe0.88CoAs2 system. We observe that both the Kohler's and modified Kohler's scalings are violated. Interestingly, the Hall angle displays a quadratic temperature dependence (cot T 2) similar to many cuprates and heavy fermion systems. The fact that this T 2 dependence is seen in spite of the violation of modified Kohler's scaling suggests that the Hall angle and magnetoresistance are not governed by the same scattering mechanism. We also observe a linear magnetoresistance in this system, which does not harbor a spin density wave ground state. Implications of our observations are discussed in the context of existing models for the magnetotransport of these strongly correlated electron systems.