Hyperthermal ion induced self-organization during the growth of carbon-transition metal films


Hyperthermal ion induced self-organization during the growth of carbon-transition metal films

Abrasonis, G.; Kovacs, G. J.; Oates, T. W. H.; Tucker, M.; Munnik, F.; Bilek, M. M. M.; Möller, W.

Spatial self organization of metal nanoparticles and quasi-continuous multilayers in carbon-transition metal (TM=Co, Ni and Cu) composite thin films as a function of metal content, metal type and incoming flux energy is investigated. Films were grown by pulsed filtered cathodic vacuum arc (PFCVA) which produces a flux of film forming species in the form of ions with ‘natural’ hyperthermal energies in the range of ~20-50 eV. Since each arc pulse deposits less than one monolayer of ions, by rapidly alternating between cathodes it is possible to deposit compounds or nanocomposites. The metal content (nominal 10-50 at.%) was varied by changing the metal to carbon pulse ratio while the incoming beam energy was controlled by applying substrate bias of 0 V, -15 V and -30 V. The structure of the films was investigated by means of transmission electron microscopy and grazing incidence small angle x-ray scattering while the film composition was determined by elastic recoil detection analysis. The results demonstrate that the vertical self-organization occurs in all type of films. At low metal contents the formation of un-correlated encapsulated nanoparticles occurs. The increase in the metal content results in the formation of a vertically layered separated nanoparticle structure with well pronounced diagonal metal nanoparticle correlations, while the further increase in the metal content results in the formation of quasi-continuous metal/carbon multilayers. The periodicity of the vertical structure strongly depends on the film composition and the incoming ion energy. The observed vertical ordering is broken down by the thermal activation of the surface diffusivity by an additional thermal heating during the deposition. The results are discussed on the interplay of stochastic thermal effects and ion induced ballistic effects.

Keywords: self organization; metal nanoparticles; composite films; pulsed filtered cathodic vacuum arc; PFCVA; hyperthermal ion energy; transmission electron microscopy; TEM; grazing incidence small angle x-ray scattering; GISAXS; elastic recoil detection analysis; ERDA

  • Poster
    2009 MRS Fall Meeting, 30.11.-04.12.2009, Boston MA, USA

Permalink: https://www.hzdr.de/publications/Publ-13501
Publ.-Id: 13501