The effects of interstitial nitrogen on the crystal and magnetic structures of new rare earth-iron-nitrogen magnets as well as the effects of cobalt nickel, manganese, aluminum, and silicon substitution for iron in these nitrided compounds will be studied. Neutron diffraction will be used to determine preferential occupancies of the substitutional elements on the different sites in crystal structure. Both neutron diffraction and Mossbauer spectroscopy will be used to determine the magnetics structures of these compounds and to reveal the detailed magnetic behavior at each of the different iron sites as a function of synthetic methods and processing techniques. The microscopic structural information from neutron diffraction and Mossbauer spectroscopy will be correlated with bulk properties as determined by magnetic measurements. Understanding in detail how the interstitial nitrogen and substitutional elements affect the iron and rare earth magnetic interactions will be an important step towards developing even better magnets.
