  The finite-temperature transport properties of FeRh compounds are
investigated by first-principles Density Functional Theory-based calculations.
The focus is on the behavior of the longitudinal resistivity with rising
temperature, which exhibits an abrupt decrease at the metamagnetic transition
point, $T = T_m$ between ferro- and antiferromagnetic phases. A detailed
electronic structure investigation for $T \geq 0$ K explains this feature and
demonstrates the important role of (i) the difference of the electronic
structure at the Fermi level between the two magnetically ordered states and
(ii) the different degree of thermally induced magnetic disorder in the
vicinity of $T_m$, giving different contributions to the resistivity. To
support these conclusions, we also describe the temperature dependence of the
spin-orbit induced anomalous Hall resistivity and Gilbert damping parameter.
For the various response quantities considered the impact of thermal lattice
vibrations and spin fluctuations on their temperature dependence is
investigated in detail. Comparison with corresponding experimental data finds
in general a very good agreement.
