Melting of dust plasma crystals with defects

The role of defects in the melting transition of a bilayer dust plasma crys tal with vertical alignment is studied using Langevin molecular dynamics si mulations. Two types of defects are considered: (i) point defects and dislo cations and (ii) additional particles which are placed below and above the bilayer crystal (i.e., the so-called strong defects). It is shown that the presence of point defects and a few dislocations does not change the two-st ep melting scenario previously found for nondefect bilayer crystals. This c ontrast with the influence of the strong defects which leads to a substanti al increase of the kinetic energy of particles and to local heating of the bilayer dust crystal.