Atomic transport in ion mixed Pd/Co bilayer

Abstract

Isotropic and anisotropic atomic transport in an ion beam mixed Pd/Co bilayer have been studied from the shifts of a marker layer in Rutherford backscattering spectroscopy. A thin layer of Au (1 nm) was embedded as a marker at the interface between Pd and Co layers. 80 keV Ar + was used to irradiate the marker sample at 90K. The Pd/Co system shows near isotropic atomic transport ( J Pd/ J Co = 0.86) due to the thermal spike effect. We present a simple relationship between the ration of atomic fluxes induced by ion mixing and the activation energies for the normal impurity diffusion of constituents in a bilayer to describe quantitatively the isotropic and anisotropic atomic transport in thermal spike induced ion mixing. Thermal spike induced atomic transport is closely related with the activation energy for normal impurity diffusion.