Growth mechanism and stress relief patterns of Ni films deposited on silicone oil surfaces

The growth mechanism and stress relief patterns of nickel (Ni) films, deposited on silicone oil surfaces by a thermal evaporation method, have been studied systematically. Our experiment shows that the growth mechanism of the Ni films approximately obeys a two-stage growth model. Characteristic cracks with sinusoidal appearance resulted from the internal stress can be frequently observed in the continuous Ni films after the samples are removed from the vacuum chamber. Several crack modes including the regularly sinusoidal cracks, zigzag cracks, attenuation cracks and self-similar cracks are described and analyzed by using the general theory of buckling of plates in detail. The internal stress and propagating velocity of the sinusoidal cracks are also discussed in this paper.