The 57Fe Mössbauer spectroscopy has been used to follow the appearance of magnetic order and structural transition induced by composition or temperature changes in some Fe-pnictide compounds. In the case of doped compounds by F, K and Na in CeFeAsO1-xFx, Ba1-xK xFe2As2 and Sr1-x Na x Fe2As2 superconductivity was established. The studies have been performed on some RFeAsO1-xFx (R = Ce, Nd) polycrystalline samples of as well as in Ba0.5K0.5Fe2As2 and Sr0.5Na0.5Fe2As2 single crystal samples. Other Mössbauer studies have shown evidence for magnetism and superconductivity on Sr4V2O6Fe2As2, and Sr4Sc2O6Fe2As2 would show a magnetic ordering without a homogeneous structure. The magnetic transition temperature and the type of transition will be discussed, as well as the coexistence of magnetism and superconductivity.
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