  We study room-temperature generation and detection of pure spin currents
using lateral spin-valve devices with Heusler-compound electrodes, Co$_{2}$FeSi
(CFS) or Fe$_{3}$Si (FS). The magnitude of the nonlocal spin-valve (NLSV)
signals is seriously affected by the dispersion of the resistivity peculiarly
observed in the low-temperature grown Heusler compounds with ordered
structures. From the analysis based on the one-dimensional spin diffusion
model, we find that the spin polarization monotonically increases with
decreasing the resistivity, which depends on the structural ordering, for both
CFS and FS electrodes, and verify that CFS has relatively large spin
polarization compared with FS.
