  Using four-terminal nonlocal magnetoresistance measurements in lateral
spin-valve devices with Si$_{\rm 0.1}$Ge$_{\rm 0.9}$, we study pure spin
current transport in a degenerate SiGe alloy ($n \sim$ 5.0 $\times$ 10$^{18}$
cm$^{-3}$). Clear nonlocal spin-valve signals and Hanle-effect curves,
indicating generation, manipulation, and detection of pure spin currents, are
observed. The spin diffusion length and spin lifetime of the Si$_{\rm
0.1}$Ge$_{\rm 0.9}$ layer at low temperatures are reliably estimated to be
$\sim$ 0.5 $\mu$m and $\sim$ 0.2 ns, respectively. This study demonstrates the
possibility of exploring physics and developing spintronic applications using
SiGe alloys.
