A disk drive includes a drive housing and a storage disk rotatably coupled
to the drive housing. In one embodiment, the storage disk includes a
first substrate, a spaced-apart second substrate, a damping layer and a
rigid substrate spacer. The first substrate is formed from a first
material having a first composition and the second substrate is formed
from a second material having a second composition. The damping layer is
positioned at least partially between the first substrate and the second
substrate. The rigid substrate spacer is positioned at least partially
between the first substrate and the second substrate, and is formed from
a third material having a third composition that is different from the
first composition and the second composition. In one embodiment, the
first composition is different than the second composition. The first
substrate has a first thickness and the second substrate has a second
thickness that can be different than the second thickness. In another
embodiment, the disk drive includes a disk clamp having an upper portion
and a lower portion. The rigid substrate spacer can be at least partially
positioned directly between the upper and lower portions.