Surface Morphology and Nanohardness of Fullerite–Aluminum Films

Abstract

The surface morphology, elemental composition, and nanohardness of thin fullerite–aluminum films with different atomic fractions of metal are investigated by scanning electron and atomic-force microscopies, X-ray spectral microanalysis and nanoindentation. The films are obtained by the method of resistive evaporation in vacuum from a combined atomic-molecular flux of Al atoms and C60 molecules on singlecrystal silicon substrates with the surface orientation (111). It is established that during deposition on unheated substrates, a nanocrystalline structure of films with an atomic fraction of metal of 20, 25 and 35%, with an average size of structural elements of 10, 15, and 25 nm, respectively, is formed. At the same time, internal mechanical stresses arise in the films, the relaxation of which leads to the exfoliation of significant sections of the film. During the deposition of films on substrates heated to 420 K, films with an average size of structural elements of 50–100 nm without exfoliation are formed, but in this case the nanohardness of the films decreases compared to the films obtained on unheated substrates.