Diffusion processes in metal/ceramic interfaces under heavy ion irradiation

Ion beam techniques are frequently used to modify the physical properties o f interfaces, Ion beam mixing and radiation enhanced diffusion (RED) of sev eral metal-ceramic interfaces were investigated. Polished Al2O3, SiO2 and M gO crystals were chosen as substrates. Thin metal films of Fe, Ni and Cu, w ith a thickness of 70 nm, were evaporated onto these substrates using Molec ular Beam Epitaxy (MBE). The bilayer systems were irradiated with 150 keV A r+ ions with a dose of 2x10(16) Ar-/cm(2) in a temperature range from 77 to 373 K. Film thickness and ion energy were so chosen as to obtain a maximum nuclear stopping power at the interface, calculated by the computer code T RIM, Rutherford Backscattering Spectrometry (RBS) was used to determine the concentration depth profiles and the diffusion lengths for each of the ele ments, Different diffusion processes. i.e. ballistic mixing and radiation e nhanced diffusion. were separated using the low and medium temperature data . The results are compared with other known systems, (C) 1999 Elsevier Scie nce B.V. All rights reserved.