Character of variation in the microhardness of the (0001) plane of Zn single crystals under the action of electrostatic field and the possible reason for this effect

The influence of electric potential on the microhardness of the crystallographic plane (0001) of zinc single crystals has been studied. It has been established that the microhardness decreases with an increase in the supplied potential and, at the value of 0.05 V, reaches saturation. The total decrease in the microhardness is 8%. It has been shown that the variation of the microhardness is statistically significant. The observed effect has been explained by a reduction in the surface energy density due to electrization of the surface. The reduction in the surface energy with allowance for the existing single layer of adsorbed water has been estimated.