Compositionally modulated ripples induced by sputtering of alloy surfaces
V B Shenoy1, W L Chan, E Chason
1Division of Engineering, Brown University, Providence, Rhode Island 02912, USA. Vivek_Shenoy@brown.edu
Physical Review Letters
|August 7, 2007
Summary
Ion beam sputtering of alloy surfaces creates nanoscale ripples and compositional changes. The degree of this kinetic alloy decomposition depends on ion flux and temperature, impacting surface properties.
Area of Science:
- Materials Science
- Surface Science
- Ion Beam Modification
Background:
- Ion beam sputtering commonly induces periodic nanoscale ripple patterns on material surfaces.
- Understanding surface evolution under ion bombardment is crucial for materials engineering.
Purpose of the Study:
- To investigate the simultaneous formation of surface topography and compositional modulations on alloy surfaces during ion sputtering.
- To determine the influence of ion flux and temperature on kinetic alloy decomposition.
Main Methods:
- Simulated sputtering of amorphous and crystalline alloy surfaces using ion beams.
- Analysis of surface topography and compositional changes as a function of ion flux and substrate temperature.
Main Results:
- Ion sputtering of alloys leads to spontaneous compositional modulations, independent of or in phase with ripple topography.
- Kinetic alloy decomposition is tunable by altering ion flux and temperature.
- Decomposition scales linearly with ion flux at high temperatures/low flux and inversely at low temperatures/high flux.
Conclusions:
- Differences in sputter yields and surface diffusivities drive kinetic alloy decomposition during ion sputtering.
- The observed compositional changes are a direct consequence of the sputtering process and material properties.
- Control over ion flux and temperature offers a pathway to tailor alloy surface composition and structure.
