  The role of the growth conditions in the spin transport properties of silver
(Ag) have been studied by using lateral spin valve structures. By changing the
deposition conditions of Ag from polycrystalline to epitaxial growth, we have
observed a considerable enhancement of the spin diffusion length, from
$\lambda_{Ag}$ = 449 $\pm$ 30 to 823 $\pm$ 59 nm. This study shows that
diminishing the grain boundary contribution to the spin relaxation mechanism is
an effective way to improve the spin diffusion length in metallic
nanostructures.
