Excimer laser-induced intermixing in irradiated Co/Ag nanometric bilayers and trilayers

Ag/Co bilayers and Co/Ag/Co trilayers were studied in order to extend our previous results on the excimer laser-induced grain boundary diffusion in Ag/Co layered structures, used in giant magnetoresistance devices. The e-beam deposited structures were processed by KrF excimer laser at the fluences F=0.1–0.25 J cm−2 with 1–1000 pulses. The temperature and depth of melting vs. time evolutions were computed for the first laser pulse. Samples were studied by X-ray reflectivity (XRR), X-ray diffraction (XRD), grazing incidence XRD, Rutherford backscattering spectrometry (RBS) and resistometry. The intermixing phenomena at the Ag/Co solid–solid, liquid–solid and liquid–liquid interfaces were quantitatively characterized. It was shown that in the immiscible Ag/Co combination of metals the interfaces could become sharper under laser processing, probably due to the back-diffusion effect.