Etude par spectrometrie mössbauer de ZnMn3 et de la transition antiferro-ferromagnetique de GaMn3 C dopes au fer 57

Abstract Mossbauer measurements have been performed on 57 Fe-doped GaMn 3 C and ZnMn 3 C. A strong variation of hyperfine field parameters at the antiferro-ferromagnetic transition of GaMn 3 C is related to the variation of the transferred fields and to the electronic anisotropy. The direction of spins is [111] for ferro and antiferromagnetic GaMn 3 C and [001] for ferromagnetic ZnMn 3 C.