Study Of The Surface Of Metallic Nano Material

Metal nano-material as a kind of nano-material has been used widely recently for its unique characteristics (such as high hardness, air-sensitive, pressure-sensitive, heat-sensitive, magnetism, etc.). They can function as coating material, sensors and micro-nano devices. However, it is difficult to manufacture the metal nano-materials, so is the study on the mechanism of the nano-materials. Given this, molecular dynamics simulation as a research method can be used to perform the interaction among a large number of molecular. It makes the study of the microscopic world of the nano-materials possible. This paper’s work is based on molecular dynamics simulation platform developed by our laboratory. The surface effects on the metal nano-materials were studied in detail.1. The flat surface was studied. Because the crystal plane face is a key factor to the surface. We studied a series of different surfaces (Their crystal plane faces were different). We found that the position of the initial dislocation changes as the surface changes. And the surface with (1000) and (10 10 0) crystal plane indices could strengthen the nanowire while the surface with (1040) and (10 7 0) could weaken. When the temperature increases, the differences between the nanowires with different surfaces decrease gradually. The result shows the crystal plane indices (CPI) as a surface factor, plays an important role in the deformation of the metallic nanowire.2. Based on the above results, the surface’s crystal plane indices is set to spherical surface. The models studied were solid nanospheres and hollow nanospheres. The study found that the atomic average potential energy of the gold hollow nanospheres is higher than the solid nanospheres. But it is the existence of the hollow structure that makes the hollow nanospheres can absorb some extent of the pressure during the compression. The appropriate internal and external diameters will make the hollow nanospheres own a stable potential energy. Further, the outer surface (10 10 0) is more prone to slip than the outer surface (10 0 0). The hollow structure weakens the difference of the (10 10 0) and (10 0 0). Higher temperature makes the difference between the gold nanospheres more unapparent.