Microstructural and electrical behavior of NiCr/Al nanomultilayered films prepared by magnetron sputtering

The NiCr/Al nanomultilayered films with different Al thicknesses (t(Al)) were prepared by magnetron sputtering. The structural evolution of the Al nanolayer with the increase in t(Al) was investigated. When the Al layer thickness changed from 1.2 nm to 2.4 nm, the Al layer could keep the co-epitaxial growth with the adjacent NiCr layer. Accordingly, the crystallization degree improved. When the Al layer thickness changed from 2.4 nm to 3.0 nm, the transformation from the coherent to incoherent interfaces took place between the NiCr and Al layers. Meanwhile, the co-epitaxial growth with the adjacent NiCr nanocrystallites was destroyed, the crystallinity and the grain size decreased, leading to the increase of the resistivity under the combined effects of the grain boundary scattering and interface scattering. The interfacial evolution of NiCr/Al nanomultilayered films was closely related to the changes of electrical properties. When the Al layer thickness changed from 3.0 nm to 3.6 nm, the surface quality of the film was improved, which effectively reduced the scattering of defects and vacancies during the electron transport, resulting in the decrease of the resistivity of the NiCr/Al nanomultilayered film. (c) 2022 Published by Elsevier B.V.

Automated summary

The effects of different Al thicknesses on the structural evolution of NiCr/Al nanomultilayered films were investigated. It was found that within a certain range, the Al layer could maintain co-epitaxial growth, resulting in improved crystallinity. As the Al layer thickness increased, the interfacial evolution changed, leading to decreased crystallinity, grain size, and increased resistivity. However, a larger Al thickness could improve the surface quality, reducing defect and vacancy scattering and resulting in decreased resistivity.