Characteristic mechanical properties and complex ordered structures in metal films on liquid substrates

Several metal (such as aluminum, iron etc.) film systems deposited on liquid (silicone oil) substrates have been successfully fabricated by a thermal evaporation method, and the special me- chanical properties and complex ordered surface structures have been systematically studied. The experimental results show that there exists a com- pressive stress gradient in these films, making cracks nucleate at the film edges and then extend to the central regions gradually. Because the interaction between solid films and liquid substrates in the tan- gent direction is very small, the metal films can mo- tion freely on the oil surfaces as a whole. In order to release the compressive stress, the broken film pieces collide, crush and superpose each other, which finally results in the formation of ordered band- shaped structures with an anti-symmetric character- istic. Based on the special mechanical properties of these nearly free sustained films, the morphologies and growth behaviors of the ordered structures are analyzed and discussed in detail.