  The electrical resistivities of Fe-Co alloys owing to random alloy disorder
are calculated using the Kubo-Greenwood formula. The obtained electrical
esistivities agree well with experimental data quantitatively at low
temperature. The spin-polarization of Fe50Co50 estimated from the conductivity
(86%) has opposite sign to that from the densities of the states at the Fermi
level (-73%). It is found that the conductivity is governed mainly by
s-electrons, and the s-electrons in the minority spin states are less
conductive due to strong scattering by the large densities of the states of
d-electrons than the majority spin electrons.
