Magnetotransport properties in the magnetic phase of BaFe$_{2-x}$T$_x$As$_2$ (T = Co,Ni): A magnetic excitations approach

Abstract

Because of their complex Fermi surfaces, the identification of the physical phenomena contributing to electronic scattering in the Fe-based superconductors is a difficult task. Here, we report on the electrical resistivity, magnetoresistance, and Hall effect in two series of BaFe$_{2-x}$T$_x$As$_2$ (T = Co, Ni) crystals with different values of $x$. The T contents were chosen so that the majority of the investigated samples present an intermediate magnetically ordered state and a superconducting ground state. We interpret the obtained results in terms of scattering of charge carriers by magnetic excitations instead of describing them as resulting uniquely from effects related to multiple-band conduction. Our samples are single crystals from the structural point of view and their overall magnetotransport properties are dominated by a single magnetic state.