Etude d'abondances dans un échantillon d'étoiles de métallicité intermédiaire entre le disque et le halo galactiques

This work is devoted to the study of abundances in mildly metal-poor stars. We have selected 21 unevolved stars with one tenth of the solar metallicity and very similar atmospheric parameters. Such a homogeneous sample has allowed us to detect, at a given metallicity, the small abundance variations which are of cosmic origin, and especially those of the neutron capture elements.