The occurrence of the modulational instability (MI) in transverse dust
lattice waves propagating in a one-dimensional dusty plasma crystal is
investigated. The amplitude modulation mechanism, which is related to the
intrinsic nonlinearity of the sheath electric field, is shown to destabilize
the carrier wave under certain conditions, possibly leading to the formation of
localized envelope excitations. Explicit expressions for the instability growth
rate and threshold are presented and discussed.Comment: 5 pages, no figures; submitted to Physics of Plasma