  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.
