Deposition of TiNi thin films on Ni(001) substrate using molecular dynamics simulation

This paper investigates the effect of incident energy and substrate temperature on the morphological and microstructural properties of TiNi thin films deposited on Ni substrate. The detailed analysis of surface morphology, the interface intermixing, density, and the voids in TiNi thin films was performed by molecular dynamics simulation combined with the second nearest-neighbor modified embedded-atom method interatomic potential (2 NN MEAM). The results indicate that higher incident energy and substrate temperature affect morphological properties of TiNi thin film. When the incident energy ranges from 0.1 to 10 eV, the surface roughness initially increases before eventually decreasing. Regarding the substrate temperature, the roughness decreases initially from 300 K to 700 K, but beyond 700 K, it begins to increase again. In addition, the interface mixing analysis was also affected by incident energy. It is found that, the thickness of the mixing interface was increased as the incident energy increase. This suggests that the growth mode changes from epitaxial to mixing. When the incident energy is higher than 10 eV, the diffusion rate of Ti atoms in the substrate layers is higher than that of Ni atoms. Conversely, at the surface of thin film, the concentration of Ni atoms is higher than that of Ti atoms. However, the substrate temperature has no significant effect on the change in interface thickness. The density of the TiNi thin films shows a significant dependence on the incident energy, but not affected by the substrate temperature. In addition, the result reveal that the increasing both the incident energy and the thickness of thin films reduces the concentration of voids and vacancies.