The horizontal and vertical oscillation modes of monolayer plasma crystal a
re investigated and are related to dust-dust and dust-plasma interactions.
It is found that the dust particles in the plasma sheath excited by a biase
d wire show parametric resonances. This parametric resonance is identified
as the reason for the observed "sublimation" transition of the plasma cryst
al from a solid to a gaslike state. (C) 1999 American Institute of Physics.
[S1070-664X(99)00807-1].