Breakdown of ZnSe under conditions associated with water tree formation

Prolonged exposure of chemical-vapor-deposited, polycrystalline ZnSe to 10 kV at 500 Hz and a 1-molal NaCl solution results in severe mechanical damage. The damage is in the form of defects which originate at the surface and grow into the bulk with a bushlike morphology. The damage path is predominantly intergranular. Neither exposure to the salt solution in the absence of the high electrical field nor electrolytic exposure alone produces the defects