INFLUENCE OF ARGON BEAM IRRADIATION AT DIFFERENT TEMPERATURES ON THE STRUCTURAL PROPERTIES OF CU/FE BILAYERS. Echeverría, G.^(1,3), Desimoni, J.⁽²⁾, Mercader, R. C.⁽²⁾, and Punte, G.^(1), (1) PROFIMO, (2) TENAES, Departamento de Física, UNLP, CC 67, 1900 La Plata, (3) Facultad de Ingeniería, UNLP, La Plata, Argentina

Ion-beam mixing rates of bilayers of metals are presently the subject of intense research. Several mixing kinetics theories have been proposed that take into account the chemical driving force between the constituting elements. However, previous Rutherford Backscattering Spectrometry (RBS) results obtained after low temperature irradiation of Fe/Cu bilayers could not be fitted whith the models available in the literature [1]. In this work, Cu/Fe bilayers grown by alternate deposition of Cu and Fe layers of 1000 Å thickness, on a Si(111) substrate and irradiated with a 360 keV Ar²⁺ ion beam (at room temperature and at 180K) with doses from 2.0x10¹⁵ to 5.0x10¹⁶ ions/cm², were studied by means of a conventional X-ray powder diffractometer. Both sets of samples show an increase in the Fe layer cell parameter as a function of the doses. However, the evolutions of Fe line-widths and positions, and Cu line-widths differ in the samples irradiated at r.t. and at 180K. These results are compared with RBS studies performed on the same samples and discussed in the frame of current ion-beam mixing theories.

[1] B. Rauschenbach, M. Posselt, R. Grötschel, E. Brecht, G. Linker, and O. Meyer, Nucl.Instr.Meth. B69 (1992) 277.