Electronic transport in magnetically ordered Mn 5 Si 3 C x films

${\mathrm{Mn}}_{5}{\mathrm{Si}}_{3}{\mathrm{C}}_{x}$ films exhibit antiferromagnetic or ferromagnetic behavior depending on the carbon doping level $x$. We report a detailed electronic-transport study of films prepared with different $x$. All films exhibit metallic behavior of the temperature-dependent resistivity $\ensuremath{\rho}(T)$ with a logarithmic increase towards low temperatures attributed to the structural disorder and the accompanied scattering of conduction electrons by two-level systems. Below $1\phantom{\rule{0.3em}{0ex}}\mathrm{K}$, the Kondo-type behavior $\ensuremath{\rho}(T)\ensuremath{\sim}\ensuremath{-}\mathrm{ln}\phantom{\rule{0.2em}{0ex}}T$ shows a crossover to Fermi-liquid behavior $\ensuremath{\rho}\ensuremath{\sim}\ensuremath{-}{T}^{2}$ independent of the type of magnetic order. The magnetoelectronic properties such as Hall effect and magnetoresistance show clear differences characteristic for the different magnetically ordered phases, i.e., antiferromagnetic vs ferromagnetic.