Résumé: Electronic and magnetic properties of bulk and films of FeGe2 are investigated within ab initio density functional theory. Bulk structure displays an anti-ferromagnetic ground state with Fe magnetic moment of 1.36[mu]B and a ferromagnetic configuration a few mRy above. Thin films with a few monolayers display a ferromagnetic ground state with a metastable anti-ferromagnetic configuration a few mRy above. A transition from ferromagnetism to anti-ferromagnetism is observed when the thickness of the film is increased. A strong increase of the magnetic moments, up to 2.64[mu]B, on Fe atoms present at the surface is observed.

Langue: Anglais