On the growth of segregated C layers on top of Fe films on pyrolytic graphite samples during high-influence D/sup +/ irradiation at elevated temperature

Journal Article · Mon May 01 04:00:00 EDT 1989 · J. Appl. Phys.; (United States)

DOI:https://doi.org/10.1063/1.342656· OSTI ID:6310262

Santaniello, A; Moeller, W; Roth, J

On Fe films evaporated on pyrolytic graphite, thick C layers segregate during high-temperature (above about 800 K) light ion irradiation if the penetrating ions are energetic enough to reach the Fe-graphite interface. The thickness of the C segregated layer and the C depth distribution in the Fe film have been determined with 2-MeV /sup 4/He/sup +/ Rutherford backscattering. A steady-state carbon overlayer is reached at high fluences (above about 10/sup 19/ particles/cm/sup 2/), the thickness of which depends on the energy of the irradiating beam for a given thickness of the Fe evaporated film. The anisotropic structure of the pyrolytic graphite substrate influences the thickness of the steady-state C overlayer, thicker C layers being measured for edge-oriented C substrates. Using the Monte Carlo code t-smcapsr-smcapsIm-smcaps, the production of defects in the graphite substrate has been calculated for different thicknesses of the C overlayer. The total amount of defects produced in the graphite substrate has been identified as the parameter regulating the growth and the steady-state value of the C overlayer. With the depth distributions of defect production generated by t-smcapsr-smcapsIm-smcaps as source functions, the diffusion of C interstitials in graphite under the influence of recombination with vacancies has been modeled. The segregating C fluxes are identified with the fluxes of interstitials arriving at the Fe/graphite substrate interface for a suitable choice of the parameters in the diffusion equation.

• Research Organization: Max-Planck-Institut fuer Plasmaphysik, Euratom Association, D-8046 Garching/Muenchen, Federal Republic of Germany
• OSTI ID: 6310262
• Journal Information: J. Appl. Phys.; (United States), Journal Name: J. Appl. Phys.; (United States) Vol. 65:9; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

656003* -- Condensed Matter Physics-- Interactions between Beams & Condensed Matter-- (1987-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CARBON
CHARGED PARTICLES
COATINGS
COLLISIONS
CRYSTAL GROWTH
DEUTERIUM IONS
DIMENSIONS
ELASTIC SCATTERING
ELECTRON MICROSCOPY
ELEMENTAL MINERALS
ELEMENTS
FILMS
GRAPHITE
HELIUM IONS
HIGH TEMPERATURE
INTERFACES
ION COLLISIONS
IONS
IRON
LAYERS
METALS
MICROSCOPY
MINERALS
NONMETALS
PYROLYTIC CARBON
RUTHERFORD SCATTERING
SCANNING ELECTRON MICROSCOPY
SCATTERING
SUBSTRATES
SURFACE PROPERTIES
THICKNESS
THIN FILMS
TRANSITION ELEMENTS